mistake that left seven innocent children and three innocent adults, including an aid worker for an american company, dead. >> i offer my profound condolences to the family and friends of those who were killed. our investigation now concludes that the strike was a tragic mistake. >> reporter: the deadly attack came just three days after a suicide bomber killed 13 american service members and some 170 afghans at the kabul airport. the pentagon said intelligence indicated another attack was imminent. so for eight hours, u.s. drones then followed a car they thought had linked up with isis-k. officials say when the driver loaded the vehicle with what they thought were explosives, a hellfire missile was launched. even days later the chairman of the joint chiefs supporting the strike. >> we had very good intelligence that isis-k was preparing a specific type vehicle at a specific type location.