On June 21, 1974, during the afternoon, Seattle Police Officer James M. Forbes died in the line of duty. Officer Forbes was a Police Helicopter Obsever in "Air 3," which was piloted by Officer James St. Delore. The officers were responding to a shooting in the south end of the city. As they flew above Beacon Hill, the helicopter collided with a Cessna 150 that was landing at Boeing Field. The mid-air collision killed both officers and the two occupants of the plane.

Officer James M. Forbes was survived by his wife Belva, sons John and Jack, and daughter Jennifer.