He got burned as a student pilot in world war two. This is out of wikipedia. Somewhere I might still have a picture I took of him and a old GF of mine once at a pow wow in tehatchipi california. He lived in the area along with chuck conners and noah beery. They used to hang out at kellys resturant in tehatchipi.
"With the outbreak of the Second World War, Palance's boxing career ended and his military career began as a member of the United States Army Air Forces. Palance's rugged face, which took many beatings in the boxing ring, was said to have become disfigured while bailing out of a burning B-24 Liberator bomber during a training flight over southern Arizona, where he was a student pilot. His distinctive gaunt look, it was said, was what he was left with after plastic surgeons had done the best that they could for him. The story of Palance's reconstructed face was repeated numerous times, including in respected film reference works, but upon his death several obituaries of Palance quoted him as saying that the entire story had been contrived: "Studio press agents make up anything they want to, and reporters go along with it. One flack created the legend that I had been blown up in an air crash during the war, and my face had to be put back together by way of plastic surgery. If it is a 'bionic face,' why didn't they do a better job of it?"