Hugh Jennings' life was filled with several tragic accidents. There was the beaning incident in Philadelphia that left him unconscious for three days. While attending Cornell, he fractured his skull diving head-first into a swimming pool at night, only to find the pool had been emptied. In December 1911, Jennings came close to death after an off-season automobile accident. While driving a car given to him by admirers, Jennings' car overturned while crossing a bridge. In the crash, Jennings again fractured his skull, suffered a concussion of the brain, and broke both legs and his left arm. For several days after the accident, doctors were unsure if Jennings would survive.
The physical abuse and blows to the head undoubtedly took their toll. During the 1925 season and he suffered a nervous breakdown when the season ended. Jennings retired to the Winyah Sanatorium in Asheville, North Carolina. He did return home to Scranton, Pennsylvania, spending much of his time recuperating in the Pocono Mountains. In early 1928, Jennings died from meningitis in Scranton, Pennsylvania at age 58.