and by the frontline journalism fund, with major support from jon and jo ann hagler. and additional support from the charina endowment fund. ♪ >> narrator: cox's bazar, bangladesh. this is the largest refugee camp in the world. reporter evan williams has come here to investigate a campaign by the myanmar military that has driven hundreds of thousands of rohingya muslims from their homes. >> williams: so arriving in the camps, it's really hard to convey the sheer scale of this crisis. we've been walking through this main camp for about ten minutes, it seems to go on and on. everywhere you look, there are more tents, more families, just ridge after ridge of shelters for these refugees. (people talking in background) >> narrator: the mass exodus of the rohingyas became world news in august 2017. but the military's campaign against them in fact began years earlier. since 2012, a small network of citizen activists has been secretly filming the reality of life for the rohingyas in myanmar. we've been given hundreds of their videos, some by an international human rights grou

and by the frontline journalism fund, with major support from jon and jo ann hagler, and additional support from joseph azrack and abigail congdon. >> (translated): for many years, terrorism was something hypothetical, something that happened elsewhere. but at a certain point, you have to open your eyes. how did we not see this coming? >> narrator: in early 2015, belgian police, with the help of u.s. and french intelligence, were preparing to launch a raid on a terrorist cell thought to be on the verge of an attack. the suspects were hiding out in the town of verviers. (speaking french) >> (translated): they were clearly in contact with people who could have turned them in. but nobody did. these people were extremely careful, they never left the apartment. we knew we would face determined men. they had weapons, they had explosives. (gunfire) >> narrator: when belgian commandos stormed the hideout, they came under heavy fire. (shouting and gunfire) they shot two men dead and wounded another. investigators found explosives, fake ids, and police uniforms. >> (translated): we discovered they ha

and by the frontline journalism fund, with major support from r.wgbh.org >> for more on this and other programs, visit our website at pbs.org/frontline. ♪ available on dvd.nstein" to order, visit shop.pbs.org or call 1-800-play-pbs. "frontline" is also available for download on itunes. ♪ you're watching pbs vofrom north to south america. man 1: these buildings are all cestially aligned. vo: with unique systems of science, art, and writing. man 2: this knowledge has been accumulated overrs vo: with unique systems of scthousands of yeawriting. vo: connected by shared knowledge and beliefs. man 3: the past is also part of the present. vo: discover a remarkable new view of native america. this fall. only on pbs. fox: climate change is affecting communities all over the world. water sources are fluctuating dramatically, crop yields are diminishing, and long-held farming techniques are being estioned. but community leaders have been pro-active. they are enging with the international community and seeking innovative methods to find sustainable wayiving. i

and by the frontline journalism fund, with major support from jon and jo ann hagler. and additial support from joseph azrack and abigail congdon. (rain pouring, thunder rbling) (man speaking spanish): (wom speaking spanish): (man speaking spanish): (woman speaking spanish): (man speaking spanish): (thunder rumbling) (wind whipping) looking live at the hurricane slamming the island we speak... >> maria's massi size dwarfing the island... >> oh, my god! >> no part of it spared. >> prayers are needed. >> laura sullivan: hurricane i maria barrelnto puerto rico last september, the worst stormh it the island in 90 years. >> the region was still tobounding from the last srm, irma, when maria rolled in. >> this storm was a tropical storm that all of a sudden in a8 span of 36ours, became a category-five hurricane. >> the winds are ferocious right now. >> 155 miles an hour.. ak ripping buildings apart. (man and woman sg spanish) >> i w worried about flooding.e- >> nin to 11-foot storm surge, upwards of twoeet of rainfall. >> and ias worried about overall damage inuc infrasre an