Van Heflin was to play the role of Hoop, but died before filming began. The part was eventually played by Ernest Borgnine.
The film was a huge flop at the box office.
Ernest Borgnine initially had trouble getting into character to play the unhinged villain Hoop. As he was in the midst of a messy divorce from his fourth wife at the time, he decided to rope in his acrimonious feelings regarding his wife, which helped him find the tenor of his performance.