additional support is provided by the abrams foundation: committed to excellence in journalism. the park foundation, dedicated to heightening public awareness of critical issues. the john and helen glessner family trust. supporting trustworthy journalism that informs and inspires. 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 mi

additional support is provided by the abrams foundation: committed to excellence in journalism. of critical issues. the jo and helen glessner family trust. supporting trustworthyur lism that informs and inspires. and by the frontline journalisms fund, with majport from jon and jo ann hagler. ca ptioned by media access group at wgbh access.wgbh.org for more on this and other programs, visit our website at pbs.org/frontline. ♪ "frontline's" "weinstein" is available on dvd. 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 celestially aligned. vo: with unique systems scienc. man 2: this knowledge has been accumulated overth sands of years. vo: connected by shared knowledge and beliefs.as man 3: tt is also part of the present. vo: discover a remarkable new view of native america.is thall. only on pbs. foxgclimate change is affect communities all over the world. water sources are fluctuating dramatically, crop yields areg, diminishnd long-held fa

additional support is ovided by the abrams foundation: committed to excellence in journalism. rk foundation, dedicat to heightening public awareness of critical issues. the john and helen glessner family trust. supporting trustworthy journalism that informs and inspires. and by therontline journalism fund, with major support from jon and jo ann hagler. and additional support from joseph azrack and abigail congdon. captioned by media access group at wgbh access.wgbh.org >> for more on this and other programs, visit our website at pbs.org/frontline. ♪ ♪ "frontline's" "blackout in puerto rico" is available on dvd. to order, visit shop.pbs.org or call 1-800-play-pbs "frontline" is also available for download on itunes. ♪ you're watching pbs george lopez: 'charlotte's web' leslie sta : 'war and peace' john green: 'the catcher george lop the rye'lotte's web' vo: but what is america's favorite book? gabrielle union: 'the color rple' allison williams: 'frankenstein' wil wheaton: 'ready player one' vo: we've got a list of america's one hundred best-loved novels, and us need you to help

additional support is providedby he abrams foundation: committed to excellence in journalism.e rk foundation, dedicated to heightening public awarenesss of criticaes. the john and helen glessner family trust.wo supporting truhy journalism that informs and spires. 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