Post Civil War, General Custer was chasing a buffalo on his horse. Custer was using a single action revolver and the buffalo rammed into them. The impact caused Custer to jerk the trigger on his cocked single action and shoot the head of his horse.
Then he was on foot out in the middle of no where.
The 1911 was only intended for cocked and locked carry when secured in the issue flap holster, and even then only cocked and locked immediately before going into battle.
Normal carry was either with empty chamber or hammer down on a round in the chamber.
The original carry for the M1911 was round in the chamber, hammer down, in the flap holster. The military of the time was used to carrying their Colt SAA's that way. The early M1911's had wide hammer spurs and the grip safety did not interfere with thumb cocking or de cocking. Obviously someone dropped the hammer because later SOP's require the thing to be carried cocked and locked in the flap holster. That was still too dangerous and Vietnam veterans report they were not allowed to put a loaded magazine in a M1911 till they were in the helicopter and they were not allowed to chamber a round till they were on the ground in the hot zone.
Accidental Discharge of a 1911 in a Thumb Break Holster