Editing Apollo 1 (section)

=== The fire ===
[[File:Apollo 1's Command Module - GPN-2003-00057.jpg|thumb|upright|Command module exterior, blackened from the eruption of fire]]
[[File:Apollo One Recording.ogg|thumb|Audio recording from the ground loop, starting from Grissom's "talk between buildings" remark. The first mention of fire is heard at 1:05.]]

The crew members were using the time to run through their checklist again, when a momentary increase in AC Bus{{nbsp}}2 voltage occurred. Nine seconds later (at 6:31:04.7), one of the astronauts (some listeners and laboratory analysis indicate Grissom) exclaimed "Hey!", "Fire!",<ref name="aibreport" />{{Reference page|page=5–8}} or "Flame!";<ref>{{Cite book |last=Slade |first=Suzanne |title=Countdown: 2979 Days to the Moon |publisher=Peachtree |others=Illustrated by Thomas Gonzalez |year=2018 |isbn=978-1-68263-013-6 |location=Atlanta |page=18}}</ref> this was followed by two seconds of scuffling sounds through Grissom's open microphone. This was immediately followed at 6:31:06.2 (23:31:06.2 GMT) by someone (believed by most listeners, and supported by laboratory analysis, to be Chaffee) saying, "[I've, or We've] got a fire in the cockpit." After 6.8 seconds of silence, a second, badly garbled transmission was heard by various listeners (who believed this transmission was made by Chaffee<ref name="aibreport" />{{Reference page|page=5–9}}) as:
* "They're fighting a bad fire—Let's get out{{nbsp}}... Open 'er up",
* "We've got a bad fire—Let's get out{{nbsp}}... We're burning up", or
* "I'm reporting a bad fire{{nbsp}}... I'm getting out{{nbsp}}..."
The transmission lasted 5.0 seconds and ended with a cry of pain.<ref name="aibreport" />{{Reference page|pages=5-8, 5-9}}

Some blockhouse witnesses said that they saw White on the television monitors, reaching for the inner hatch release handle<ref name="SP4029" /> as flames in the cabin spread from left to right.<ref name="aibreport" />{{Reference page|page=5-3}}

The heat of the fire fed by pure oxygen caused the pressure to rise to {{convert|29|psi|kPa|abbr=on}}, which ruptured the command module's inner wall at 6:31:19 (23:31:19 GMT, initial phase of the fire). Flames and gases then rushed outside the command module through open access panels to two levels of the pad service structure. The intense heat, dense smoke, and ineffective gas masks designed for toxic fumes rather than smoke, hampered the ground crew's attempts to rescue the men. There were fears the command module had exploded, or soon would, and that the fire might ignite the solid fuel rocket in the launch escape tower above the command module, which would have likely killed nearby ground personnel, and possibly have destroyed the pad.<ref name="SP4029" />

As the pressure was released by the cabin rupture, the rush of gases within the module caused flames to spread across the cabin, beginning the second phase. The third phase began when most of the oxygen was consumed and was replaced with atmospheric air, essentially quenching the fire, but causing high concentrations of carbon monoxide and heavy smoke to fill the cabin, and large amounts of soot to be deposited on surfaces as they cooled.<ref name="SP4029" /><ref name="aibreport" />{{Reference page|pages=5-3, 5-4}}
 
It took five minutes for the pad workers to open all three hatch layers, and they could not drop the inner hatch to the cabin floor as intended, so they pushed it out of the way to one side. Although the cabin lights remained on, they were unable to see the astronauts through the dense smoke. As the smoke cleared they found the bodies, but were not able to remove them. The fire had partly melted Grissom's and White's nylon space suits and the hoses connecting them to the life support system. Grissom had removed his restraints and was lying on the floor of the spacecraft. White's restraints were burned through, and he was found lying sideways just below the hatch. It was determined that he had tried to open the hatch per the emergency procedure, but was not able to do so against the internal pressure. Chaffee was found strapped into his right-hand seat, as procedure called for him to maintain communication until White opened the hatch. Because of the large strands of melted nylon fusing the astronauts to the cabin interior, removing the bodies took nearly 90 minutes. The bodies were only able to be removed after 7.5 hours from the time the incident took place, due to the gasses and toxins present which prevented medical personnel from entering initially.<ref name="SP4029" />

Deke Slayton was possibly the first NASA official to examine the spacecraft's interior.<ref name="Leopold">{{Cite book |last=Leopold |first=George |title=Calculated Risk: The Supersonic Life and Times of Gus Grissom |publisher=[[Purdue University Press]] |year=2016 |isbn=978-1-55753-745-4 |location=West Lafayette, Indiana |pages=259–260}}</ref> His testimony contradicted the official report concerning the position of Grissom's body. Slayton said of Grissom and White's bodies, "it is very difficult for me to determine the exact relationships of these two bodies. They were sort of jumbled together, and I couldn't really tell which head even belonged to which body at that point. I guess the only thing that was real obvious is that both bodies were at the lower edge of the hatch. They were not in the seats. They were almost completely clear of the seat areas."<ref name="Leopold" /><ref>{{Cite web |title=#72 D. K. Slayton February 8, 1967 |url=https://history.nasa.gov/Apollo204/appendices/AppendixB.pdf |archive-url=https://ghostarchive.org/archive/20221009/https://history.nasa.gov/Apollo204/appendices/AppendixB.pdf |archive-date=October 9, 2022 |url-status=live |access-date=August 17, 2018 |website=Apollo 204 Review Board Final Report |publisher=NASA |page=B-162}}</ref>