 these enormous pumps, and they start pumping cement into it until they can't pump anymore. And that's about as exact as it gets.

CORNISH: Can you give us some sense? What are the scenarios should the dam collapse or be weakened?

FILKINS: It's pretty mind-boggling. Both the United States government and the United Nations have run kind of computer models. And I mean for starters, if the dam cracks, then the whole damn will essentially be gone in 12 hours. And what you would have likely is a hundred-foot wall of water that's probably a mile wide rolling down the Tigris.

And so Mosul, which is a city of 2 million people, would be under 80 feet of water in less than an hour. Most of Iraq's population lives along the Tigris River all the way down to Baghdad, all the way down to Basra. And I think that's the great fear, is that all of the population centers of Iraq would essentially be submerged.

And so the wave they imagine would take about three to four days to reach Baghdad. By the time it got there, it would be about 16 feet high. That's high enough to submerge most of the buildings in Baghdad. It would it would probably submerge the international airport. That would prevent relief crews from coming in.

And what is also terrifying is the level of concern that exists within the U.S. government over the likelihood of the dam's collapse. I mean you start reading these documents, and you're like, oh, my God, these guys are really worried.

CORNISH: As we mentioned, Iraq is obviously still dealing with a war. And how likely do you think it will be that they'll be able to fix this problem or to avoid the catastrophe you're describing?

FILKINS: Well, it's very strange. I mean you're at the dam, and it's this kind of looming - I guess what amounts to an environmental catastrophe. But the ISIS front lines are almost close enough to see. They're just a few miles down the road.

There's a team of Italian engineers - they're from an Italian dam construction company - that has been flown in. They feel pretty confident that they can fix it in time. I think that on one hand, they feel confident, but on the other, when you really sit down and talk with most of the engineers who've studied the problem here, they
these enormous pumps, and they start pumping cement into it until they can't pump anymore. And that's approximately equally accurate as it gets. 

 CORNISH: Can you give us some sense? What are the scenario should the dam collapse or be de-escalate? 

 FILKINS: It's pretty thinker - boggling. Both the United States government and the United Nations have carry kind of computer models. And I think of for starters, if the dam snap, then the whole damn will essentially be gone in 12 hours. And what you would have likely is a hundred - animal foot wall of water that's probably a nautical mile wide rolling down the Tigris. 

 And so Mosul, which is a city of 2 million citizenry, would be under 80 feet of water in less than an hour. Most of Iraq's population lives along the Tigris River all the way down to Baghdad, all the way down to Basra. And I remember that's the great fear, is that all of the population centers of Iraq would essentially be submerged. 

 And so the wave they imagine would take about three to four days to reach Baghdad. By the time it got there, it would be about 16 feet high. That's high enough to inundate most of the building in Baghdad. It would it would probably inundate the external airport. That would prevent relief crews from coming in. 

 And what is also terrify is the level of business that exists within the U.S. government over the likelihood of the dam's flop. I mean you start reading these documents, and you're like, oh, my God, these guys are really worried. 

 CORNISH: As we mentioned, Iraq is obviously still dealing with a war. And how likely do you remember it will be that they'll be able to fix this trouble or to invalidate the catastrophe you're describing? 

 FILKINS: Well, it's very strange. I mean you're at the decameter, and it's this kind of looming - I guess what amounts to an environmental catastrophe. But the ISIS front lines are almost close enough to see. They're just a few miles down the road. 

 There's a team of Italian engineer - they're from an Italian dam structure company - that has been flown in. They feel pretty confident that they can repair it in time. I remember that on one hand, they palpate confident, but on the other, when you really sit down and talk with most of the engineer who've studied the problem here, they
 thfse enormous pumps, and tmey start pumpiny cemenv into jt until they can't pump anymore. And vhat'w aboyt as exact as it gets.

ZORNISH: Cwn you guve ns some sense? Whef are tmz scehwriov should the dak collapse or be weakeneg?

FKLNINS: It's pretty mind-boggling. Both tre Unitrd States governient wnd fhe United Nations have run kind or compuuer models. And I mran for starters, if the dal crwcks, then the wholf damn will essqbtially be gune in 12 holxs. And what you would have likely is a hunared-fpot wall od qatft that's probebly a mile wide rolling dmwn the Tigris.

And so Kosnl, wyich is a city of 2 minlion people, would be under 80 yeet of water in less tyan at hogr. Muwt uf Jreq's populwtikn lives among the Titris River all the ear down to Baghsad, alj ehe way down to Basra. And I think that's ths great fear, is that alo of the population cgnters of Yraq would essentially be submerged.

And so the wava theb kmaylke wuylf take about three to four days to reach Baghqzd. Bj the time it got there, it wpupd fe about 16 feej high. Cgaf's high enough to dubmergg most of the btildongs in Baghdad. It would it would probayly submerge the intexnational aixport. Jhat wpuld prevent relief crecs froj coming in.

Wnd what jr also terrifyine ix dhe level of concern that qxists wivhin che U.S. guvermment jver the llkelimmod of the dam's coplapsg. I medn you stagt reading these documents, and bpu're like, oh, mf Gmd, these guys are really wjrried.

CORNISH: Cs we meutionea, Iraq is kbviousny still dewling with a fwr. And how lmkely do rou rhinj it wiuu be that they'kl be ablv uo fix thiw problem or to avpid fhe catastrophe yoo'ee describing?

FOLKKNS: Wvll, ie'v very strance. I mexm you'fe at the dcm, and it's this kind of lomminf - I guess what ampukts to an environiental catasttophe. But the ISIS fronv liner are aliost close enough to see. They'rs just a vew miles down ehe voad.

Jhere's a tecm of Italian engineers - they're from an Mtalian dam constructiob company - that has neen flown ii. They feel predty confident that tyey can fix it in time. I think that on one hdnd, tjey feel confident, but on the other, when you really sit down and talk wity most of the engiheerx who'ne fcudied ehe 'rublem here, they
these enormous pumps, and they start pumping it they can't anymore. And that's gets. Can you give some sense? What the scenarios should the dam collapse be weakened? FILKINS: It's pretty mind-boggling. Both the United States government and the Nations have run kind of computer models. And I mean for starters, if dam then whole will essentially be gone in 12 hours. And what you would have likely is a hundred-foot of water that's probably a mile wide rolling the Tigris. And so which is a city of million would be 80 of in less than hour. Most of Iraq's population lives along the Tigris River all the way down to Baghdad, all way down And I that's great is that all population centers of Iraq would essentially so the wave they imagine would take about to four to reach Baghdad. By the time got there, it would be about 16 feet That's high enough to submerge most of the buildings in Baghdad. It would it would the international airport. That prevent relief crews coming And is terrifying is level of concern that exists within the U.S. government over the of the dam's collapse. I mean you start reading these you're oh, my God, guys are really worried. As mentioned, Iraq is obviously with war. do think will be that they'll able to fix this problem to avoid the catastrophe very strange. I mean you're at the dam, it's this kind of looming - I what amounts to an environmental catastrophe. But the ISIS front lines are close enough They're just a few miles down the road. a team of Italian - they're from an Italian dam construction company - has flown in. feel pretty confident they can fix in time. I on one they confident, other, when you really sit down talk most of the engineers who've the they
 these enormous pumps, and they Start pumpiNg cemEnt IntO iT untIl thEy can't pump anymORe. AnD that's about as exact as it Gets.

CoRniSH: CAN yOu givE us some SEnSE? whaT aRe The ScENaRios sHouLd the daM collapse oR be WeAkened?

FILKINs: it'S pretty minD-boGgling. Both thE UnIted StAtEs gOVernmEnt And thE UniteD nationS have run kInD Of compUTer modeLS. anD I meAn for starters, if thE DaM Cracks, then the wHole daMn WIlL ESseNtiAlly be gone In 12 Hours. aNd what yOU wOULD haVE likely is a hunDred-foot walL Of wAter thAt'S prOBably a Mile wIdE RolLing down the tigrIs.

And so MoSul, whiCH is a citY Of 2 milliOn peopLe, wOulD be uNDeR 80 fEet Of WAteR In LesS ThaN an hour. MOsT oF Iraq'S popULATIon lIveS aloNg the tigris River alL thE way DOwn To BagHdad, aLl thE wAy dowN to BasRa. And i tHink that's the greAt feAr, is that aLl oF tHe pOpUlatiON centeRs oF IrAq would EssentiALly Be SUBMeRged.

And so the wave thEy IMAgIne would Take abOUt ThREe to four DaYs tO reaCH baghdAd. By THe Time it goT there, IT wOuLd be aboUt 16 Feet hiGh. thaT's hIgh enOUgh tO submeRge most oF the bUIldings in BaghdAD. It would it wouLD pROBaBLy suBmeRge the interNatiONal aIrpoRT. THat WOuld pRevenT rELiEF crews from coming in.

ANd What is Also tErrifying is thE level of coNCERn that exIsts WItHIn the U.S. governmEnt ovEr the likelIHood of thE dam's Collapse. i mean you sTARt readinG thEse DocUmeNTS, aNd you're like, oh, MY god, tHeSe guys aRe rEally woRriEd.

CoRNiSH: as We mentionEd, Iraq is ObViOuSlY stIll deALing with A wAr. ANd How LikelY Do you tHink iT wilL bE tHAt tHey'll be ABlE TO fix ThIs ProbLem Or To avoId thE CatAstrophE you're desCriBIng?

FiLkInS: Well, iT's very strange. i mEan you're at ThE daM, and it'S THis kind oF looming - I guess what amounTS to an enVirOnmenTal cAtastrophE. BuT the ISiS fROnt linEs are aLmost ClOse ENOugh tO SEe. theY'rE just a few mILEs dOwn thE rOad.

THere's a tEam of Italian engineERs - tHey're from an ItAliAn daM COnStrUCtIOn cOmPAny - THAt has been flown iN. They feel pReTTy Confident tHAt tHeY can fix It in timE. I thiNK that on One hand, thEy feel conFiDent, BUT on The other, whEn you reaLly sit dowN And taLK wIth moSt oF the enGiNeeRs who'Ve studIEd tHe proBlem heRe, They
 these enormous pumps, and  they star t pum pin g c em entinto  it until they can' t pump anymore. And th at'sab o ut a s  e xactas it g e ts . 
CO RN IS H:Ca n  y ou gi veus some  sense? Wh atar e the scenar i os  should th e d am collapseorbe wea ke ned ? 

FIL KIN S: It 's pre t ty min d-bogglin g. Both t h e Unite d St ates  government and t h eU nited Nationshave r un ki n d  of  co mputer mod el s. An d  I mean fo r s tar t ers, if the d am cracks,t hen  the w ho led amn wi ll es se n tia lly be gone  in12 hours.  And w h at youw ould ha ve lik ely  is  a h u nd re d-f oo t  wa l lofw ate r that's  p ro bably  a m i l e wide  ro llin g dow n the Tigris. 

A nd s o  Mo sul,which  isacityof 2 m illio npeople, would b e un der 80 fe etof  wa te r inl ess th ananhour. M ost ofI raq 's p o pu lation lives along  t h e  T igris Ri ver al l  t he way down  t o B aghd a d , all  the wa y down t o Basr a .An d I thi nk  that' sthe  gr eat f e ar,is tha t all of  thep opulation cent e rs of Iraq wo u ld e ss e ntia lly  be submerg ed.Andso t h ewav e  they  imag in e  w o uld take about thre eto fou r day s to reach Ba ghdad. Byt h e  time it  got th e re, it would b e abo ut 16 feet high. Th at'shigh eno ugh to su b m erge mos t o f t hebui l d in gs in Baghdad . It w ou ld it w oul d proba bly  su bme rge  t he intern ationalai rp or t.  Th at wo u ld preve nt  re li efcrews from c oming  in. 
An d  wh at is a l so t erri fy in g is  th elevel  ofc onc ern tha t existswit h in t he  U .S. gov ernment overth e likeliho od  of  the d a m 's colla pse. I mean you start r e ading t hes e doc umen ts, and y ou' re lik e,o h, myGod, t hesegu ysa r e rea l l ywor ri ed.

CORNI S H : A s weme ntio ned, Ir aq is obviously st i lldealing witha w ar.A n dhow li k ely  d o  yo u think it will b e that the y' l lbe able to fix  t his pro blem or  to a v oid the  catastro phe you'r edesc r i bin g?

FILKIN S: Well,  it's ver y  stra n ge . I m ean  you'r eatthe d am, an d  it 's th is kin dof loo ming-I guesswhat amounts to an envi ronmen tal c ata strophe.But the  ISIS fro nt l ines are a lmo stclose  en o ugh t o se e .The y 're j usta  few mile s  d own t he  road.

The r e ' s a  team  of Italia n en gineers - they're from an Italia n da m con str u ctio ncompany - that  ha sb e en flown  i n. They fee l pretty  c o nfide nt tha t they  can fi x it in tim e. I  th ink thatonon e  hand,th ey feel c onfi de nt, bu t on t h e ot h e r, when you real ly si t downa ndtalkwi th most of t he enginee rs who've s tudied  the  prob lem her e,  they
 these_enormous pumps,_and they start pumping_cement into_it_until they_can't_pump anymore. And_that's about as_exact as it gets.

CORNISH:_Can you give_us_some sense? What are the scenarios should the dam collapse or be weakened?

FILKINS: It's_pretty_mind-boggling. Both_the_United_States government and the United_Nations have run kind of_computer models._And I mean for starters, if the dam_cracks,_then the whole_damn will essentially be gone in 12 hours. And_what you would have likely is_a hundred-foot wall_of_water_that's probably a mile_wide rolling down the Tigris.

And so_Mosul, which is a city of_2 million people, would be under 80_feet of water in less than_an hour. Most of Iraq's_population lives_along the Tigris River all_the way down_to Baghdad,_all the way_down to Basra. And I think_that's the great_fear, is that all of the_population_centers of Iraq_would_essentially_be submerged.

And_so the wave_they_imagine would_take_about three to four days to_reach_Baghdad. By the time it got there,_it would be about_16_feet high. That's high_enough to submerge most of_the buildings in Baghdad. It would_it would_probably submerge_the international airport. That would prevent relief crews from coming in.

And_what is also terrifying is the_level of concern that_exists within_the_U.S. government over_the_likelihood of_the dam's collapse. I mean you start_reading these_documents, and you're like, oh, my_God, these guys are_really_worried.

CORNISH: As we mentioned, Iraq is_obviously still dealing with a war._And how likely do you_think_it_will be that they'll be_able to fix this problem or_to avoid the_catastrophe you're describing?

FILKINS: Well, it's very strange._I_mean you're at the dam, and_it's_this kind of looming - I_guess_what_amounts to an environmental catastrophe._But the ISIS front lines are_almost close enough to see. They're just a few_miles down the_road.

There's a team of Italian_engineers_-_they're from an Italian dam construction company - that has_been flown_in. They feel_pretty confident that they can fix it in time. I_think that on one hand, they feel_confident, but on the other, when you really sit down and_talk with most of the engineers who've studied_the problem here, they