During my PPL days at Biggin Hill there was a report of a Cessna 337 twin (engine front and rear) whereby a passenger disembarked, walked around the back of the a/c and into the still rotating prop with tragic consequences.
The other occasion was on the Doolittle raid on Tokyo 1942 where a sailor on the a/c carrier slipped over on the deck and lost an arm as start up orocedures commenced .