Apollo 1 Astronauts Killed

1967: Apollo 1 astronauts Gus Grissom, Ed White and Roger Chaffee are killed in a fire during a test of the command module on the ground. It is unclear what started the fire, but since a high-pressure 100 percent oxygen atmosphere was being used, the tiniest spark could have set it off. At the time, the hatch in the command module was designed to open inwardly, and the high pressure meant it was impossible for the astronauts to open it and escape. The hatch was subsequently redesigned to open outwardly in order to avoid a similar accident in the future.