Final answer:
The Apollo 1 mission ended in tragedy when a fire in the command module resulted in the deaths of astronauts Gus Grissom, Ed White, and Roger B. Chaffee.
Step-by-step explanation:
The Apollo 1 mission was a tragic event in the history of space exploration. The three men who lost their lives in the Apollo 1 fire were Gus Grissom, Ed White, and Roger B. Chaffee. These astronauts were undergoing a simulation test on the launch pad at Cape Kennedy, Florida, when a fire broke out in their command module. Unfortunately, due to the pressurized pure oxygen environment and complications with the module's escape hatch, they were unable to escape the fire and tragically died on January 27, 1967.
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