pushed the launch into 1967. The launch of Apollo 1 was planned for February 21, 1967. The crew entered the spacecraft at 13:00 on January 27, mounted atop its Saturn IB booster on Launch Pad 34 at Cape Kennedy, for a "plugs-out" test of the spacecraft. The test was to demonstrate all of the space vehicle systems and procedures, which included an abbreviated countdown and flight simulation. It was not classified as hazardous since the rocket would not be fueled during the test. The test's progress was delayed by problems with a cabin odor and poor communications between the ground stations and the crew. At 18:31, a fire broke out in the pure oxygen-filled cabin, killing all three crewmen. Emergency roles had called for White to actuate the inner hatch release handle; then, Grissom would assist him in the removal of the cover, while Chaffee would maintain communications. White had apparently tried to do his part: his body was found in his center seat, with his arms reaching over his head toward the hatch. Removing the cover to open the hatch was impossible because the plug door design required venting normally slightly greater-than-atmospheric pressure and pulling the cover into the cabin. Grissom was unable to reach the cabin vent control to his left, where the fire's source was located. The intense heat raised the cabin pressure even more, to , at which point the cabin walls ruptured. The astronauts were killed by asphyxiation, smoke inhalation, and thermal burns. Aftermath The fire's ignition source was determined to be a spark that jumped from a wire on the far left of the spacecraft, under Grissom's seat. Their deaths were attributed to a wide range of lethal hazards in the early Apollo Command Module design: workmanship and conditions of the test, including the highly pressurized 100% oxygen pre-launch atmosphere, many wiring and plumbing flaws, flammable materials used in the cockpit and the astronauts' flight suits, and a hatch which could not be quickly opened in an emergency. After the incident, these problems were fixed, and the Apollo program carried on successfully to reach its objective of landing men on the Moon. White was buried with full military honors at West Point Cemetery while Grissom and Chaffee are both buried in Arlington National Cemetery. NASA officials attempted to pressure Patricia White, his widow, into allowing her husband also to be buried at Arlington, against