"The night before the launch, Ebeling and four other
engineers at NASA contractor Morton Thiokol had
tried to stop the launch. Their managers and NASA
overruled them.
That night, he told his wife, Darlene, "It's going to
blow up."
..."
http://www.npr.org/sections/thetwo-way/2016/01/28/464744781/30-years-after-disaster-challenger-engineer-still-blames-himself