she said, "we believe warren is in north waziristan. please make sure you don't accidentally kill him." what happened. >> president obama: i want to express our grieve and condolences to the families ofican, dr. warren weinstein and an italian giovanni laporto, who wered in a u.s. counter terrorism operation. >> stahl: the president said that after hundreds of hours of it was determined that it housed only terrorists. it wasn't until after the strike that they realized warren andage were also there. c.i.a. director john brennan and lisa monaco went to elaine'slain to the family what happened, a meeting that has not been disclosed until now. >> elaine weinstein: it was first day. >> stahl: and you articulated this? >> elaine weinstein: yeah, i did. to the people that we said, "don't do this."cknowledged that they did it and they-- they goofed. >> stahl: so how did lisa monaco react? >> elaine weinstein: shery. she grabbed a tissue and she said "i know." >> stahl: the president called took full responsibility for the death of her husband.

believed that warren was being held in north waziristan, a prime target area for the strikes. she says she told lisa monaco of her fears in january 2014. >> stahl: she had the foresight to worry that the bombing could affect her husband? >> lebson: of course. she said, "we believe warren is please make sure you don't accidentally kill him." and it's exactly what happened. >> president obama: i want to express our grieve and condolences to the families of two hostages: one american, dr. warren weinstein and an italian giovanni laporto, who were tragically killed in a u.s. counter terrorism operation. >> stahl: the president said that after hundreds of hours of surveillance over the compound, it was determined that it housed only terrorists. it wasn't until after the strike that they realized warren and the other western hostage were also there. c.i.a. director john brennan and lisa monaco went to elaine's daughter's home to explain to the family what happened, a meeting that has not been disclosed until now. >> elaine weinstein: it was like, "i told you so." i was worried about