What was the name of spacecraft in which the first three astronauts were killed?

Apollo 1 was scheduled to be the first manned mission to the Moon. On January 27, 1967, a cabin fire during a launch pad test at Cape Canaveral killed all three crew members (pictured). The ignition source was never identified, but many lethal design and construction flaws were identified after the accident. The manned phase of the project was delayed for 20 months while those problems were corrected.