On June 6th, 1944, Lieutenant James Doohan of the Royal Canadian Artillery came ashore on Juno beach. He had to run through a minefield under machine gun and mortar fire, before taking out two German snipers and silencing a machine gun nest. He survived the landing only to be shot by one of their own sentry guards, with a Bren gun, when coming back from a courier run.
He was shot 4 times in the left leg, once in the chest and one round hit his middle finger on his right hand. What was left of the finger had to be amputated. If you watch Star Trek closely, you can see that he only has 3 fingers on his right hand. The round that hit him in the chest deflected off a silver cigarette case that his brother had given him. He kept that cigarette case as a good luck charm and said that smoking had saved his life. (You can see his missing finger in the image below.)
He later became a pilot for artillery spotting and was labeled as "the craziest pilot in the Canadian Air Force".