The mission was officially designated Apollo/Saturn 204, but more commonly known as Apollo 1. In this close-up view of the interior of the Command Module shows the effects of the intense heat of the flash fire which killed the prime crew during a routine training exercise are shown. While strapped into their seats inside the Command Module atop the giant Saturn V Moon rocket, a faulty electrical switch created a spark which ignited the pure oxygen environment. The speed and intensity of the fire quickly exhausted the oxygen supply inside the crew cabin. Unable to deploy the hatch due to its cumbersome design and lack of breathable oxygen, the crew lost consciousness and perished. They were: astronauts Virgil I. "Gus" Grissom, (the second American to fly into space) Edward H. White II, (the first American to "walk" in space) and Roger B. Chaffee, (a "rookie" on his first space mission).