Died Sept. 12, 1946 while he and Detective Ben Johnston were arresting two men who were suspects in the death of Officer Jerry St. Clair. They approached the suspect vehicle at 1500 S. Frisco Avenue. The suspects exited the vehicle and began firing. Detective Cormack was killed and Detective Johnston wounded. A 17 year old suspect was wounded and captured at the scene. The other suspect was later arrested in Idaho.