The windows shook as dynamite aboard an airplane exploded over Conrad Hopp's family farm in northern Colorado 70 years ago.
Hopp, then 18 years old, saw a ball of fire streaking across the night sky and rushed with his brother toward where the burning wreckage came down, dodging objects that turned out to be the bodies of victims of the first confirmed case of sabotage against a commercial U.S. airliner.
