text: how did apollo 1 really burn up?   the fire is believed to have been caused by a spark somewhere in the capsule's 30 miles (50 km) of wiring. due to the pure oxygen inside the capsule (which was at a pressure of 15 psi or 100 kpa) the fire was quickly out of control. the apollo 204 review board determined that a silver-plated copper wire running through an environmental control unit near the command module pilot's couch had become stripped of its insulation and abraded by repeated opening and closing of an associated access door. this weak point in the wiring also happened to pass near a junction in an ethylene glycol/water cooling line, which had developed a leak. the electrolysis of ethylene glycol solution with the anode made of silver resulted in a violent exothermic reaction that ignited the ethylene glycol mixture, which in turn was able to burn in the atmosphere of pure pressurized oxygen.[1] a similar march 1961 incident had previously claimed the life of soviet cosmonaut trainee valentin bondarenko when the pure oxygen atmosphere in the isolation chamber he had been occupying had caught fire, a calamity the ussr had, for years, concealed from the public. the nasa investigation found that a bar of aluminum can burn like wood in a pure oxygen atmosphere. it also found substandard wiring in the craft and a missing socket wrench that was ruled out as the fire's cause. many items on board were flammable, and flammable velcro had been applied to the walls of the craft to secure items in weightless conditions.  the fire spread quickly and within seconds was an inferno. as a result of toxic smoke and malfunctioning gas masks, ground crew needed five minutes to open the hatch and suppress the flames. the fire had melted the astronauts' space suits and the air lines which connected them to the capsule's life support systems. grissom's and white's suits were found to have fused together. it was evident from how the corpses lay that they had tried to get out, but they never had a chance. ed white, who was supposed to open the hatch, was partway out of his harness and had apparently made an effort to escape. the procedure would have had grissom lower white's headrest, and white proceed to unlatch over 12 bolts to release the hatch. indeed, even if he were to accomplish that, the internal pressure had risen so high that the inward-opening hatch could not have been opened. chaffee's job was to begin shutting down the spacecraft and maintain communications with ground control. he was found dead still strapped into his right hand seat. only 17 seconds from the first call of "fire!", all three were dead.  it was later confirmed that the crew had actually died of smoke inhalation rather than burns. according to the report of the apollo 204 review board — appendix d panel 11, (link provided below), grissom suffered third degree burns on 36% of his body (1st, 2nd and 3rd degree burns covered 60% of his body) and his spacesuit was 70% destroyed. white suffered third degree burns on 40% of his body (1st, 2nd and 3rd degree burns covered 48% of his body) and his spacesuit was 25% destroyed. chaffee suffered third degree burns on 23% of his body (1st, 2nd and 3rd degree burns covered 29% of his body) and his spacesuit was 15% destroyed.