The Crane is flown with a two man crew, the rear seat is seldom, if ever used, since the advent of vertical reference operations. It was most typically used for construction over any other operation and would certainly never see use in firefighting.
Initial reports suggest the focus of the investigation is on maintenance activities on the main rotor servo. Heavylift is now reportedly removed from the Forest Service contract and their remaining 54A and 53D grounded.
This also shows one of the great hazards in this design, the exposure and relative structural weakness of the cockpit from the rest of the airframe.
Amazing sequence of pictures! Incredibly lucky for everyone in the aiercraft and on the ground.