the crew of Apollo 1 was killed when fire engulfed their spacecraft during a ground test. The disaster stalled America's race to the moon for a year and a half. See how the Apollo 1 fire tragedy happened in our full infographic.
From left, Apollo 1 astronauts Virgil I. "Gus" Grissom, Edward White and Roger Chaffee pose in front of their Saturn 1 launch vehicle at Launch Complex 34 at the Kennedy Space Center. The astronauts later died in a fire on the pad.