In addition, lunar modules flown but not landed on the moon burned up and fell into the ocean, including the Apollo 13 lander and the plutonium it carried in a cask to protect it in the event of reentry, except for the LM used on Apollo 10. read more
The Apollo 1 flight was cancelled after a cabin fire killed the entire crew and destroyed the Command Module during a launch rehearsal test. Corrections of the problems which caused the fire were applied to the Block II spacecraft, which was used for all manned missions. read more