On Jan. 27, 1967, tragedy struck the Apollo program when a flash fire occurred in Command Module 012 during a launch pad test of the Apollo/Saturn space vehicle being prepared for the first piloted flight, the AS-204 mission. Three astronauts, Lt. Col. Virgil I. Grissom, a veteran of Mercury and Gemini missions; Lt. Col. Edward H. White, the astronaut who had performed the first United States extravehicular activity during the Gemini program; and Lt. Cmdr. Roger B. Chaffee, an astronaut preparing for his first space flight, died in this tragic accident.

A report submitted to the NASA Administrator in April 1967 presented the results of the investigation and made specific recommendations that led to major modifications and revisions to the Apollo Command Module. With these changes, the overall safety of the Command and Service module and the Lunar Module was increased substantially. The AS-204 mission was redesignated Apollo I in honor of the crew.