Soyuz 1, launched April 23, 1967, carried cosmonaut Colonel Vldaimir Komarov. He became the first in-flight fatality in any space program. Komarov knew the Soyuz 1 capsule had many flaws but decided to fly it anyway, because if he refused, his best friend Yuri Gagarin would be assigned to it.
Komarov was killed when the capsule became tangled in its parachutes and he plummeted several miles to Earth. His last words were cursing the men who built the Soyuz capsule.