this is the briefing. i'm victoria fritz. our top stories: —50 degrees — tens of millions of americans face the biggest polar vortex for 20 years. is this a disaster waiting to happen? we visit one of the 200 dams the brazilian government says are at risk of collapse. a real case of poachers turned gamekeepers — we find out how former wildlife smugglers are helping to save russia's endangered snow leopards. in business, amazon's $72 billion christmas. record sales for the online giant, but fears of a slowdown in growth rattle investors. also coming up: president hails ‘tremendous progress‘ in us china trade talks. we'll have the reaction from asia in the business briefing. a warm welcome to the programme — briefing you on all you need to know

in global news, business, and sport. and you can be part of the conversation too. shares in the "to z" tech giant slide 5%, as amazon fails to deliver for investors. today we want to know — are you an amazon believer? tell us what you think — just use the hashtag #bbcthebriefing. we start in the united states, where there's been no let—up in the icy grip on the midwest. relief is on the way but for many it can't come soon enough. arctic temperatures have left schools closed, flights grounded and there've already been deadly consequences. the polar vortex has been blamed for multiple deaths — even breathing outside is difficult. the bbc‘s chris buckler is in chicago with this update. the snow has been falling in chicago

again. and although their milder temperatures, it is still —16, —17, -18 temperatures, it is still —16, —17, —18 celsius. it does not look much warmer. look at the chicago river. it is frozen over still. there are many warnings about this river. for example, in some cases, people are worried about falling ice. beyond that, people are being told to stay out of these kind of conditions for too long because they could get frostbite. do try and demonstrate that we, along with others, have been using some pieces of clothing, wet pieces of clothing. this wet t—shirt, after a short amount of time, in this weather, is basically frozen solid. 0ther time, in this weather, is basically frozen solid. other people have been sharing those kind of pictures on social media of what this weather can do, along with spectacular pictures of what has been across the

mid west a frozen wonderland, but a dangerous one at that. further east in places like new york and boston, they have also been feeling the cold air. after the freeze is coming the door. in illinois in the last couple of days temperatures have reached as low as —35 celsius. by next week, by monday they could be as much as plus 10 celsius. that kind of rapid thaw can cause problems in itself. it could lead to potholes and flooding and problems as far as people are concerned, because it could mean burst water mains. i'll be speaking to someone in rural minnesota, one of the worst affected areas, that's in just under ten minutes. here in the uk, heavy snow has been sweeping eastwards across the country, with the south—west the worst affected so far. 12 centimetres of snow has been recorded in cornwall. there are warnings of rail delays and treacherous driving conditions in many parts — and british airways has warned that some short—haul flights to and from heathrow airport on friday morning have been

cancelled or merged. the icy conditions are expected to last into the afternoon. the number of dead from the burst dam in brazil last week the 300 dead. many are still missing. in the state where the collapse happened, at least 200 dams are classified by the government as having a high potential for damage if there was a collapse. devastation as far as the i can see. this is waste from iron ore mining in golfing houses, trees, trucks, and hundreds of people believed to be buried under the mud. the dam,

owned by mining giant vale collapsed. just over three days ago another dam collapsed. 0nly collapsed. just over three days ago another dam collapsed. only a kilometres away. now attention turns to neighbouring cities, like this one, into one of the biggest dams in latin america. this dam is owned by csm. it is right next to the city and holds five times more mining waste than the dam that collapsed. when this neighbourhood was built, the dam was a lot smaller, but it was expanded over the years, growing closer and closer to the houses. it is just 250 metres from some of the construction. and after what has happened, residents here say it is either them or the dam. they don't feel safe any more. translation: i'm terrified. iwake up translation: i'm terrified. iwake up scared. i have nightmares. ifear this could happen here too. we live

right under the dam. i am scared for eve ryo ne right under the dam. i am scared for everyone here. this activist says there is no dialogue with csn. the company did not want to comment on this report. translation: the lesson comes at a huge cost, with all the lives we lost, but it has to be applied to prevent other collapses. people here wa nt prevent other collapses. people here want a solution. they don't want to live in doubt. structural problems we re live in doubt. structural problems were detected twice in the dam in the past six years, according to this prosecutor. and were repaired following judicial orders. at the time, csn said the demands had been followed and the dam presented no risks for workers and residents. translation: it's a huge structure, very close to the city. if it breaks it is going to be one of the worst accident ever. mining workers here are concerned after the dam collapse. vale employees voted to

interrupt their shift for two hours to mourn their colleagues. translation: if it is so safe way to shareholders live under a dam? we have to change the model of mining and governments need to pressure private companies instead of using licenses for mining. after two disasters collapses, brazil's mining dams are under scrutiny and people living under their shadows don't wa nt to living under their shadows don't want to be the next victims. let's brief you on some of the other stories making the news: a court in france has sentenced two policemen to seven years in jail for raping a canadian tourist at what was then the headquarters of the parisian judicial police. the case had been rejected in an earlier trial, but the victim waived her right to anonymity to pursue the case. a third man, who's not been identified, is also suspected of raping her. the us envoy for north korea has said pyongyang has promised to dismantle and destroy all its uranium and plutonium enrichment facilities —

a commitment apparently made to the us secretary of state and to south korean leaders. north korea has made such promises before, and the us is seeking expert access to verify any removal or destruction. a funeral service has been taking place in seoul to honour kim bok—dong — a korean woman who was forced into wartime sexual slavery by japanese troops and who later campaigned for peace and women's rights. mourners gathered outside the japanese embassy to pay their respects. she was one of the first so—called ‘comfort woman‘ to speak publicly about her experiences. australia experienced its hottest month on record injanuary. government figures show that the mean temperature across the continent exceeded 30 degrees celsius. the hottest temperature of 49.5 celsius was recorded in port augusta in south australia. climate experts say the main cause was a persistent high pressure system over the tasman sea, as well as the broader trend in global warming. let‘s turn now to our

top business story — online retail giant amazon. it has broken its own records yet again — after the strongest holiday season in its history. sales jumped 20% in the three months to the end of december — to over $72 billion. but it‘s predicting a slowdown in growth — and that has rattled investors — who sold off the shares in after hours trading. with me isjoel kibazo who‘s partner atjk associates and a former director of communications at africa development bank. hello. good morning to you. thank you for coming in and braving the snow. let us talk about amazon. adi skids on amazon when it comes to growth? —— adi skids? investors are quite rattled, shares dropping 5% in after—hours trading. are you a

believer in this stop? victoria, there is no way the skids would be on amazon at this stage. the shares did fall, because the company did say that it expected the first quarter of this yearfor say that it expected the first quarter of this year for things to slow down a little bit. but it did give reasons for that. yes, slowdown, but actually slow down to a rate that we have not seen from this company since the thing is this, when you grow to such a level there is only so far you can keep going at that particular pace. one of the reasons amazon gave is that there had been a regulation changes in india, which is one of its new markets, a huge market, it has got to negotiate that. plus it will be making other investments. we do see the reasons for the decline in. i would not write off amazon just yet. there is still plenty of space for it to operate. it has services such as cloud computing, they continue

rising exponentially right across the globe. i am sure that will continue to push amazon forward. i don‘t know it will be at the same rate, but we have a long way to go. we have a story if you want to look at it on the website. our we have a story if you want to look at it on the website. 0urjeff bezos took amazon to the report. natalie schoeman saying perhaps" perhaps it jeff bezos had a crystal ball". there he is in 1987 when amazon became a public company —— 1987. there he is in 1987 when amazon became a public company -- 1987. the race continuing apace. it is the will ‘s biggest company by value. he is the richest mattis world‘s something that has not gone unnoticed. we will have you back later for the papers. venezuela‘s self—declared interim presidentjuan guaido has said his family has been threatened, amid the country‘s continuing political crisis. in a speech at venezuela‘s central university, he said police had visited his family home looking for his wife. eliza philippidis reports. standing outside his apartment block with his wife and daughter,

juan guaido said he won‘t be intimidated by agents of venezuela‘s special action forces. he has the backing of the united states, and they have warned of serious consequences if nicolas maduro‘s government harms them. so the tussle for control of venezuela goes on. translation: we continue and will continue in the street on saturday to support and accompany the ultimatum that the european union gave nicolas maduro and start talking very clearly to the armed forces and give some precise orders. we will order humanitarian aid to into the country. the eu have announced the creation of an international contact group to include european and latin american countries. the aim — to help chart a peaceful end to venezuela‘s political crisis and they‘re hoping to do it within 90 days. the purpose of the international contact group is clear. as i said, it is enabling venezuelans to express themselves, freely and democratically, through the holding

of new elections. on thursday, the government of venezuelan president nicolas maduro announced that three air force generals have been arrested, accused of plotting an uprising against his government. translation: according to information obtained by our intelligence bodies, there was an arrival from colombia of a group of hired killers, hired by the venezuelan ultra rights to commit selective assassinations against politicians and military leaders. workers from the state oil company held an anti—imperialist march after the us slapped sanctions on the firm on monday in an attempt to cut off a vital source of funding propping up nicolas maduro‘s government. millions of people remain in poverty. many have left the country looking

for a brighterfuture. the united nations said it is willing to step up humanitarian aid, but requires consent from the government led by nicolas maduro and, as yet, there is no indication that that is forthcoming. eliza philippidis, bbc news. stay with us on bbc news, still to come: a round up of the sport — including the cricket, where the west indies are in a commanding position in the second test in antigua after an england batting collapse. this is the moment that millions in iran had been waiting for. after his long years in exile, the first hesitant steps of ayatollah khomeini on iranian soil. south africa‘s white government has

offered its black opponents concessions unparalleled in the history of apartheid. and the anc leader, nelson mandela, is to be set free unconditionally. ..four, three, two, one... a countdown to a critical moment. the world's most powerful rocket ignited all 27 of its engines at once. and, apart from its power, it's this recycling of the rocket, slashing the cost of a launch, that makes this a breakthrough in the business of space travel. two americans have become the first humans to walk in space without any lifeline to their spaceship. one of them called it a piece of cake. thousands of people have given the yachtswoman ellen macarthur a spectacular homecoming in the cornish port of falmouth, after she smashed the world record for sailing solo around the world non—stop. you‘re watching the briefing. 0ur headlines: the number of people known to have been killed by the collapsed dam

in brazil has risen to 110, with 238 others still unaccounted for. the mining company has pledged to compensate the families of victims. millions of people in the american midwest have been trapped in their homes by an extreme polar vortex, with temperatures almost —50 degrees celsius. let‘s stay with that now. julia plum joins us from a small city in minnesota called bemidji, an area which has experienced some of the coldest temperatures and wind chill during this polar vortex. thank you so much forjoining us. this is the striking ring —— thing, we‘ve heard from chicago, some of the big urban centres, but where you are, not only is it cold but in terms of the impact, it is far

greater on the community. it's an incredible storm and we are used to very severe weather already but very experienced people are having great difficulty. what sort of temperatures is it reaching where you are at the moment?” temperatures is it reaching where you are at the moment? i should've looked at my celsius but i know that we had three nights in a row of —40 fahrenheit and the wind chills were down in the —60, —70 and the windchill coming across the large field is unbelievable. it was too cold to have the chemicals on the roads and the wind was too much to keep sanded down and we‘ll all the black ice, it was very dangerous, if you could get your vehicle started. just for our viewers around the world, could you paint a picture of

the town, and surrounding area, of the town, and surrounding area, of the people who live there and some of the conditions they are facing. very beautiful lake community with a couege very beautiful lake community with a college that has incredible poverty. while one part of the city lives are very extravagant life, the other side knows great poverty, especially because we have a rule poverty. we are an urban centre for a rural area, are an urban centre for a rural area , even are an urban centre for a rural area, even though we are 10,000 people, but that area are urban. cou nty people, but that area are urban. county services, housing. even if they have a couch to stay on, they still need to come to the city and ta ke still need to come to the city and take care of those problems. and they have nowhere to go. people accustomed to staying outside, even through the winter, as far as i

know, we do not have anyone outside this week. how much help have you received? is certainly a surge in support from the local community. we have an active facebook page. sometimes, they are financial gifts. they go towards wood and heat and water. 0ther they go towards wood and heat and water. other times, they go towards wood and heat and water. 0thertimes, people will they go towards wood and heat and water. other times, people will mail out codes and gloves and toilet paper. all of those things are greatly needed an unbelievably appreciated. for now, thank you so much. julia plumb, one of the worst affected areas in minnesota, from this arctic polar vortex. the situation here in the uk at heathrow, about a0 flights have been cancelled at the moment, mainly british airways flights. the vast

majority, the advice is to go check on the website. see if your flight is still running. now it‘s time to get all the latest from the bbc sports centre. hello, i‘m holly hamilton and this is your friday sport briefing. we start with cricket — and the west indies had the better of the first day‘s play in the 2nd test against england in antigua. kemar roach was the pick of the west indies‘ bowlers — with a for 30 on another wretched day for england‘s batsmen. the tourists were bowled out forjust 187 with only moeen ali and jonny bairstow showing any resistence. moeen top—scored with 6. the west indies will start the 2nd day on 30 without loss. they trail by 157. this the draw for the semi—finals of the copa del rey takes place this del rey takes place later on friday. valencia, real betis and the holders barcelona have beenjoined in the last four by real madrid.

karim benzema scored twice as they won 3—1 at girona in the second leg of their quarter—final. marcos llorente also scored for madrid, as they completed a 7—3 aggregate win. meanwhile, lazio are through to the semi—finals of the coppa italia where they‘ll face ac milan. that, after beating inter—milan on penalties in their qaurter—final at the san siro. lazio were leading 1—nil in extra—time when mauro icardio equalised for inter in the 120th minute — with a penalty. that meant penalties would decide the tie... and lucas leivas scored the winner as lazio won the shoot—out a—3 to reach the last four. the asian cup final takes place later. four—times champions japan against qatar. the qataris, who host the 2022 world cup, are the surprise package at the tournament never having got past the quarter—finals before. this group of players, they work in

the right direction with the right mentality, to be in the top of the competition. it doesn't matter what happens, we are feeling very proud about them because they are showing very high level in this competition. we are going to try to make the people in our country tomorrow happy again. and to try to make history. now, over the years, andy murray and stan wrawinka have shared a fierce rivalry on the tennis court but that rivalry has been put aside as the former world number one recovers in hospital from hip surgery. murray posted this on instagram earlier, a gift he‘d received from wawrinka and croation tennis star donna vekic, a giant life—sized teddy, with murray thanking him for the very thoughtful present insisting that his kids wil be fighitng over it when he gets home. all the latest sports news is available on the bbc sport

website. that‘s bbc.com/sport. but from me, holly hamilton, and the rest of the sport team — that is your friday sport briefing. goodbye. the snow leopard is an animal in serious danger. native to central and southern asia, there are estimated to be fewer than 10,000 of them still alive. and that figure‘s expected to go down in the coming years. but conservationists are trying to do something about it — as the bbc‘s tim allman reports. there is a bleak splendour to the altai mountains. cold and unforgiving, you have to be tough to survive here. mergen markov has lived here all his life. he is on the hunt for snow leopards — not to kill, but to photograph, these automatic

cameras helping to monitor the snow leopard population. translation: i am really happy i have this job which allows me to spend all this time outside and admire all the animals i‘ve managed to photograph. is it better than killing them? yes, they are so beautiful in the photographs. this is the village of argut. after the collapse of the soviet union, the collective farms went bankrupt. many people took to hunting the local wildlife. the fur of a snow leopard could sell for more than $500. so the world wildlife fund pays former poachers, mergen included, to try to protect them instead. translation: he quickly understood that if he kept on poaching and selling furs, he would earn money only once with each animal he‘d killed.

whereas with us, he earns money regularly. local volunteers are also paid to go on patrol and monitor this vast area of land. over time, the hope is the number of snow leopards will rise. these animals will return home. tim allman, bbc news. stay with me on bbc news, i‘ll be back with the business briefing. some tweets about amazon. whether you‘re a believer in this company. growth looks like it is snowing. sean henderson says, the brakes have been applied to amazon that only tempera sara lee. the will rise when india starts to bite into amazon. hello. there‘s more snow to come in

as forecasters we into friday. the main focus is a zone from south wales across to east anglia and south of here or driven by this area of low pressure which stays close by as we go into friday. while the earlier and the warning has expired, still a number of yellow warnings for snow and ice sit tricky travelling conditions and services. bbc local radio for updates. 3— seven centimetres on friday across central and southern england, ten centimetres across higher south england and wales. increasingly patchy. further snow showers feeding in north—east england across the north york moors to the midlands through the day. still this frequent snow across the highlands of scotla nd snow across the highlands of scotland and northern isles. another couple of centimetres on top of what we‘ve seen. a cold feeling day or

us. we‘ve seen. a cold feeling day or us. not as cold as thursday. highlands starting as low as —10. sunshine across northern ireland and southern scotland away from these wintry showers, sunshine and snow turning increasingly like sleet across southern turning increasingly like sleet across southern areas. turning increasingly like sleet across southern areas. quite windy at times, brisk northerly winds exacerbating cold. temperatures four, five celsius but they should be above freezing across northern england and scotland shrouded in fog through much of the state. friday— saturday, stream of showers on the east coast with one or two across scotla nd east coast with one or two across scotland and northern ireland. a cold and frosty night, particularly further west you are. east anglia and south—east england with further cloud. above freezing. saturday, low pressure m oves cloud. above freezing. saturday, low pressure moves away and we briefly seek high pressure developing sofa many, saturday, after a cold and frosty start, a good deal of crisp

winter sunshine. still frosty start, a good deal of crisp wintersunshine. still some frosty start, a good deal of crisp winter sunshine. still some wintry showers along eastern coast is so bringing sleet or snow. in the sunshine, four, five, six or seven celsius across south—west england. to some of the weekend, it stays cold. some sunshine, further wintry showers. perhaps some snow across scotland. this is the business briefing. amazon‘s $72 billion christmas. record sales for the online giant— but fears of a slowdown in growth rattle investors. plus, ‘tremendous progress‘. president trump hails success in us china talks — but no sign as yet of a deal to end their damaging trade war. and on the markets: a mixed day on wall street, but the recovery

from the pre—christmas sell off continues. us shares have now had their best start to the year since the 1980s.