>> good thing he's across the country. he'd be coming to our house. nbc "nightly news" is next. on this sunday night, severe weather. the threat of violent storms and tornadoes in a big part of the country tonight, with tens of millions in their path. no end in sight. the growing death toll after almost three weeks of war in gaza, and the impacts on both sides. high time, a major new call for the federal government to legalize marijuana. tonight, the arguments on both sides of the debate. and surf's up for the world's most famous dog on a board. how she has helped so many take the ride of their lives. >> announcer: from nbc news world headquarters in new york, this is "nbc nightly news" with

lester holt. good evening. we're going to start here tonight with what may be happening outside your door this evening. severe weather, violent weather system working its way from the midwest to the east tonight, with millions of people in its path. we've already seen strong thunderstorms and large hail in a vast stretch extending from illinois all the way to massachusetts. and as we look now at live radar, parts of kentucky, ohio, eastern tennessee, west virginia, and pennsylvania are under tornado watches, and what could be a very tough and dangerous night. we'll get the latest guidance on the storms in a moment. but first, nbc's john yang tells us what they've done so far. >> reporter: large hail, intense lightning, high winds and dangerous thunderstorms pushed through several states, including illinois and kentucky. triggering a tornado warnings and watches. a tornado touched down in central connecticut this afternoon with estimated winds of 85 miles an hour.

several homes were damaged in wolcott. heavy rains caused flash flooding in worcester, massachusetts, drivers pushing through several inches of rain on roadways. >> these severe storms will bring large hail, damaging winds. maybe even a strong tornado. there's also potentially deadly lightning with these storms. >> reporter: meteorologists at the national weather service headquarters in jackson, kentucky, remain on high alert. these meteorologists monitor severe storm systems, the potential for flooding, damaging winds and any dangerous weather in the region. they train for days like today, working with emergency management teams, and sending out weather warnings and advisories to residents in the danger zones. >> when we see something on the radar, we have storm spotters and chasers out there we can get their report as well. >> reporter: this round of dangerous weather produced a string of severe storms that made its way from canada to the great lakes and now stretches to the southeast. people in more than 18 states

are bracing for the threat of dangerous storms expected to continue throughout the evening. nbc news, chicago. >> for the path of these storms, let's bring in weather channel meteorologist kim cunningham. >> hey, lester, we've already had over 160 reports of severe weather today. look at this radar. look at the severe thunderstorm warnings and tornado warnings we're seeing here in parts of tennessee. the watch, as we mentioned earlier, in effect for almost all of ohio, kentucky, even parts of north carolina, until 9:00. even into pittsburgh. severe thunderstorm watch here for detroit. so tornadoes are possible with this as well. not just hail and damaging winds. here's that forecast for tonight. possibly seeing severe weather ramping up in eastern pennsylvania later on today. a watch may be expected there. watch the cold front move east tomorrow. behind it we'll cool down. ahead of it, still enough instability we may see more severe storms in the morning hours, including boston, maybe

some of the higher elevations. isolated storms behind it. southeast also looking at severe storms as the front continues to push off to the south. as i mentioned, once this goes through, we'll see a much bigger cooldown for everybody. back to you. >> kim, thank you very much. firefighters in northern california tonight are battling a wildfire that has forced hundreds to evacuate. and has destroyed at least ten homes. the so-called sand fire is in the sierra nevada foothills near the wine growing regions in el dorado county. it has grown significantly in the last day to about six square miles, and is now 35% contained. a big outbreak of a deadly ebola virus in west africa killed 670 people and now taking a toll on health care workers on the front lines. tonight we've learned of two americans who have been infected with the deadly disease. we get the latest from nbc's janet shanlian. >> reporter: we've learned a second u.s. citizen tested

positive for the ebola virus. she's been working with the aid organization samaritans first, the same charity kent brantley was serving when he became infected with ebola this week. this is dr. brantley, a 33 yrld father of two, in protective gear treating an ebola patient. dr. brantley's infection comes amid the worst outbreak. the death toll is nearing 700. there is no treatment or vaccine. the symptoms are flu-like. fever, headache, diarrhea, vomiting, weakness and stomach pain. >> ebola is probably the most contagious and deadly virus in the world. it's spread through contaminated body fluids, things like sweat, blood, saliva. >> reporter: the virus is already in the west african countries of guinea, sierra leone, siberia. it could become high spread in

highly populated innigeria and senegal. >> i think it could have a huge disruptive effect on economics, on trade, on travel, in many dimensions. >> reporter: in nigeria, international airports are screening arriving passengers for ebola, after an infected traveler from liberia died. now two americans are being treated for the virus. tonight dr. brantley is in quarantine and stable. the mother of two is receiving treatment. two americans working to save lives, now fighting for their own. nbc news, london. overseas, despite talk of a new temporary cease-fire in gaza today, both sides in that war launched new attacks as the death toll among palestinians and israelis continue to rise. we have two reports tonight. we begin with kate snow in tel aviv. kate? >> reporter: good evening,

lester. the white house is losing patience. president obama this afternoon calling the israeli prime minister once again urging him to accept an unconditional humanitarian cease-fire. but there's a new poll out tonight that really shows a lot about how israelis feel about all this. 87% do not want a cease-fire, they want the operation to continue in gaza. israel claims it was hamas who shattered the quiet first, and they retaliated. firing only when fired upon. on "meet the press," benjamin netanyahu made their position clear. if israel pulls back and stops destroying hamas tunnels, even a brief cease-fire could give hamas time to regroup. >> we can't allow them to restock this arsenal, or we'll be stuck in another five, six months with the same problem. so we want demille tarization of gaza. >> reporter: with secretary of state john kerry, u.s. officials were hoping a set of rolling cease-fires would staunch the

bleeding, while diplomats kept talking. but the two sides are entrenched. >> they're both deep into the escalation, and looking for a way out. and it gets messier and uglier and more violent as we proceed. >> reporter: throughout the day, sirens sounded in southern israel warning of incoming rockets from gaza. each time that happens, launchers like the two you see behind me part of a high-tech system, they fire israeli missiles to intercept the rockets in midair. it's happened nearly 500 times over the past few weeks. to further bolster their position, the israeli defense forces released this video today showing what it says hamas is firing rockets from a palestinian-run school in gaza. but the u.n. agency that runs other schools turned shelters said if militants are firing from their schools, it's only after they've evacuated. >> there's absolutely no evidence it's been produced in this round of fighting, certainly, that militants have gone into shelters we're using to shelter displaced people. >> reporter: the damage is

certainly greater in gaza. but even on the israeli side of the border today, civilians caught in the cross fire. kate snow, nbc news, tel aviv. >> reporter: in the gaza strip, hamas today rejected a short-term cease-fire, firing rockets into israel. and israel fired back. the fighting shattered hopes that soon there could be calm amidst the carnage. here, people are still grappling with the devastation. trying to make sense of it is this woman. she lost her home. when we met her, she was desperately trying to find any family photos. >> this is my house. >> reporter: this man found one of his fondest, a picture of his father. the family home that israel destroyed. now, along with his five brothers, their wives and dozens of kids, this family of 60 is

living here. crammed into this tiny apartment. no furniture, just clothes on their backs. local aid groups donate one meal a day and they all have to share. i work every day to give my kids everything they wanted, he tells me, and now we've lost everything. i miss my bike, his 5-year-old son tells me. it, too, was destroyed in the attack. still he and his family are the lucky ones. their home gone, but they are alive. others like baby shima are fighting to live, with every breath she takes. her mother was killed in an israeli strike. when doctors realized she was pregnant, they operated. shima was born prematurely. her aunt named her after her mother. at just three days old, she's in stable condition. born into a war that has claimed her mother, and destroyed the lives of so many more.

tomorrow is the -- one of the most religious holidays in the islamic calendar. it was supposed to be marked with joy, families celebrating with their kids, buying them toys. instead the people of gaza are going to be on a knife edge, if this war resumes in full swing once again. lester? >> ayman and kate, working both sides of this conflict for us. thank you. the fighting in libya rages on after it forced the u.s. embassy to close and more than 150 americans to evacuate the country. some of the most intense fighting between rival militias is going on around the airport in tripoli which was struck by shells today. dozens have been killed in the fighting. france, germany and britain are warning their citizens to leave libya. in this country, a manhunt intensified for two carjackers who crashed into a family selling fruit in philadelphia, killing three children. and leaving their mother fighting for her life.

we get the latest tonight from nbc's kristen dahlgren. >> reporter: ask anyone here about keisha williams, and they all say one thing -- >> loved her children. her children were her life. >> reporter: the 34-year-old mother is now fighting to survive. unaware that three of her children are gone. killed friday when two alleged carjackers in an suv plowed into them, while the family was selling fruit for a church fund-raiser. >> as a mother, would you want to tell her? all three of her children are gone? >> reporter: tia brown's mother, thelma, was with them, and is now in the hospital. >> that could be your kids laying down there. are turn yourself in. that's all i can say. >> reporter: police still haven't released much information about two suspects they say fled on foot. neighbor butch rushed to the scene when he heard the crash. >> first thing i saw was the bodies laying out in the lot. one, two, three.

>> reporter: he saw 7-year-old terrence, known in the neighborhood as his mom's shadow. 10-year-old thomas who was sweet and shy. and he tried to revive 15-year-old kiara who was about to start high school. she died at the hospital. >> that will never go away from my mind. i'll never forget that. never. >> reporter: tonight the manhunt is on. police have lifted finger prints from the suv, and found a bloody t-shirt near the crash site. while all day, mourners visited this makeshift memorial, including little terrence's stepmother. >> his smile, he was so adorable. he still is. >> reporter: a family and a neighborhood in search of healing. and answers. >> these young guys, whoever they are, did what they did to these people and then to get out and run, and leave these people for dead. >> reporter: now, there is $110,000 reward for any information leading to an arrest. but part of that expires at noon

tomorrow. meantime tonight, keisha williams remains in critical condition. today we learned she has two other children who weren't here with her, one of them has special needs. >> kristen dahlgren in philadelphia, thank you very much. we have another weather story. just word getting in of a rare severe weather outbreak in southern california, where as many as ten people were reportedly struck by lightning. most at the venice beach boardwalk. the los angeles fire department responded and revived one person who was unconscious. when "nbc nightly news" continues on this sunday, legalizing pot. a major new call tonight for the federal government to repeal the ban on marijuana. and later, surf's up for a remarkable dog helping kids with special needs.

legalizing marijuana in this country, t"the new york times" became the largest newspaper to decriminalize pot at the criminal level. many sta many states have moved on their own. >> reporter: all across the country people are using pot with fewer legal consequences. colorado and washington becoming the first two states to legalize marijuana for recreational pirps. today "the new york times" said the country needs to go further, in a long editorial the paper wrote, the federal government should repeal the ban on marijuana. comparing it to the days of

prohibition, the paper argues that like in that period, otherwise law-abiding citizens today are becoming criminals. >> $3 billion to $4 billion a year is spent on this. and there are like 600, 700,000 marijuana possession arrests a year. >> reporter: the reaction was swift. >> i don't think it's really a federal issue. >> i don't see how there would be anything so substantially beneficial to society by lifting a ban like that. >> reporter: rewind to 1992 when bill clinton ran for president and his use of marijuana was a political liability. >> i didn't like it. and didn't inhale. and never tried it again. >> reporter: compare that to candidate barack obama in 2008 who openly admitted to smoking and inhaling. 36 states, plus the district of columbia, have loosened their marijuana laws, and polls show more than 50% of americans now think it should be legalized. >> we don't care if anybody smokes, or doesn't smoke. we're just not encouraging it.

>> reporter: the "times" argued it should still be off-limits to those under 21. former congressman patrick kennedy who has admitted to battling drug addiction, said legalizing marijuana is a slippery slope. >> it will ultimately set up a marketplace for the commercialization. with the commercialization, you'll have a marketing campaign targeting kids. >> reporter: a concern shared by some other parents. >> we do not know the outcome, except that the best evidence is that you lose -- if you would use marijuana as a teenager regularly, eight iq points, but i don't have eight to lose. >> reporter: the "times" noted there is still debate about the health risks. president obama has said he thinks marijuana is no more dangerous than alcohol, but he is not expressing support for legalizing it at the federal level. meanwhile, two more states, alaska and oregon will decide whether to allow marijuana for recreational purposes later this

year. >> kristen, thanks. when we come back, it was found in a flea market. the personal meeting of this american flag for one military family.

cooperstown, new york, today. the class included pitchers greg maddox and tom glavine, frank thomas and joe torey, bobby cox and tony la russa. a special tribute to a fallen u.s. marine, after nine years, finally found its way to where it was intended to end up. with his family. and tonight an american flag signed with other messages from his unit provides comfort to his still grieving mom. as we hear from mark potter. >> reporter: patsy has always treasured the flag that draped her son's coffin nine years ago. fred was killed in a helicopter

crash in iraq. >> he told me he wanted to be a marine. he died doing what he loved. >> reporter: now come an unexpected tribute to her fallen son, from complete strangers, who found another flag with very special meaning at a texas flea market. lany brown bought the flag with her husband for only $5 because it was covered with writing. they showed it to their son, a u.s. marine. >> as soon as he looked at it, he said, dad, this is a tribute flag. everybody in the unit signs it whenever a marine falls roirt that marine was fred. through facebook, the browns were able to find patsy, his mother. and lany called her. >> she said, i want to meet you. she wanted to meet the mother of this marine that gave his life, you know. >> reporter: the browns who live four hours away wanted to present the flag in person. >> all marine kids are your kids, too. so we felt an immediate need and

responsibility to get this back to them. >> i can't wait to meet them. i can't wait. >> reporter: and so, on saturday, they did meet. and two marine moms finally got to embrace. >> i don't have my son, but at least i have this. >> reporter: as a hallowed flag finally came home. mark potter, nbc news. up next here tonight, why this dog has become a surfing phenomenon, and it's not just about riding waves.

finally tonight, on a beach near san diego, you can find a dog named ricochet, a golden retriever who loves to surf. before you start thinking this is just another story about a cute dog doing tricks, watch this report from nbc's nik taibbi. >> reporter: the word is out, kids know it, and parents like jackie know exactly what ricochet has taught kids like her 8-year-old son, hunter, born with spina bifida, and while still limited on land, liberated in the water. >> because he's in a wheelchair doesn't mean he has to stay in a wheelchair. he can get out and surf. >> reporter: there are other dogs who surf.

maybe most of them have developed some level of empathy for the moods and needs of their human pals. but ricochet is special. the owner, judy, the day ricochet first jumped on a board and helped steady the ride for a paraplegic teenager. she posted a video and 4.4 million views later, ricky was a start. >> i thought, we're getting all this attention and we certainly don't need it for ourselves. let's use it as a platform to help other people. and that's how it started. and it's never stopped. >> reporter: a website later, and ricky and judy were a fund-raising colossus, raising money for scores of charities benefiting both humans and animals. ricochet's friends are all kids or dogs. her unique calm and empathy have helped soldiers like army medic randy dexter emerge from the depths of ptsd. his hellish 27 months in iraq leaving him awash in booze and

despair. >> i was very suicidal, just at my wit's end. i had tried everything. >> reporter: everything but this. that four-legged celebrity -- >> ricochet. >> reporter: -- who can plow the road for an anxious soldier, or ride the surf with 2-year-old ka lob aboard. or take one more ride, just the two of them this time. the longest they've ever had together. all the way in, a boy and a dog. will they do it again? >> yeah. >> reporter: why wouldn't they. mike taibbi, nbc news. that's "nightly news" for this sunday. brian williams will be here tomorrow. i'm lester hold. and for all of us here on nbc i'm lester hold. and for all of us here on nbc news, good night. -- captions by vitac -- www.vitac.com