Warden was born John H. Lebzelter in 1920 in Newark, N.J. He was still in high school during the Depression when he tried his hand at professional boxing under his mother's maiden name of Costello.
He had 13 welterweight bouts in the Louisville area before joining the Navy, where he was sent to China and patrolled the Yangtze River.
He also had jobs as a nightclub bouncer, a lifeguard and a deckhand on an East River tugboat.
In 1941, he joined the Merchant Marine. He served in the engine room as his ship made convoy runs to Europe.
"The constant bombings were nerve-racking below decks," he recalled.
He quit in 1942 and enlisted in the Army. He was a paratrooper with the 101st Airborne Division but shortly before D-Day he broke his leg during a nighttime practice jump in Britain.
"They sent me back to the States," he recalled in a 1988 Associated Press interview. "I was in a hospital for nearly a year."
A fellow soldier who had been an actor gave him a play to read and he was hooked. He recovered enough to take part in the Battle of the Bulge and, after the war, went to New York to pursue an acting career.
