On August 13, 1975, Chicago Fire Department Pilot Ronald Lemar died in the line of duty when his helicopter crashed during a training exercise on Lake Michigan. Lemar and co-pilot Rudolph Allegrucci were flying a Bell G-17, pontoon-equipped helicopter during an air-sea rescue demonstration in which they “rescued” Diver Charles Thiel, who was in the water pretending to be a swimmer in distress. The pilots landed the helicopter on the water, and Allegrucci helped Thiel climb onto the pontoon on the right side of the aircraft. When the helicopter tried to take off, the right pontoon dragged in the water and caused the helicopter to tilt. The rotor blade hit the water and the helicopter was flipped upside down and caught fire. Thiel and Allegrucci were able to escape to a nearby fireboat that was there to witness the demonstration, but Lemar suffered fatal head injuries in the crash.

He was survived by his wife and three children.