The worker had been rehearsing a stunt scene that involved driving a motorcycle, Dictate 939 Hyperstrada, out of the open doors of a building, across a concrete pad and down a ramp that had been built over three stairs and coming to a stop on the stair landing.
The motorcycle struck the concrete sidewalk curb, the worker was thrown off the motorcycle and propelled through a plate glass window of a building.
During the first shooting of the scene the stunt driver continued driving beyond the planned stopping spot on the stairway landing, and continued to drive down a second ramp built over the bottom stairs and across the roadway.