and then i heard roger chassey. i could hear him screaming from pain. i could hear the pad people yelling and screaming. i could hear roger chassey then say, please get us out of here then i heard nothing. when that fire started they were probably dead in 15, 20 seconds. >>> it shocked the nation. and stunned nasa. the deaths also devastated craft who was a pallbearer in grism's funeral. >> you lost three fine men. although i've seen test pilots killed that probably helped me a little bit not a hell of a lot. >> nasa engineers ran simple tests and discovered that under high pressure oxygen everything burn, even metal. >> we didn't realize how explosive that mixture was when you got a spark. as soon as we started figuring out what happened we all started blaming ourselvesment ourselvesment -- ourselves, it was our fault. we should have been more careful. we should have thought about what that test was doing. we should have argued more about getting the things fixed that weren't fixed. there's a lot of things that belonged in that spacecraft. >> nasa fire