Abstract: At approximately 2:30 p.m. on September 27, 2012, Employee #1 and coworkers, of Valley Fire & Security Alarms, Inc., were working in a commercial building. They were installing low voltage electrical cable, part of a fire alarm system installation for a new tenant space. This work involved accessing an elevated service attic corridor. Employee #1 and coworkers entered the service attic corridor via an extension ladder. Coworker #1 spooled out the cable as Employee #1 walked the cable down the corridor, attaching it along the wall as he went. Employee #1 stepped away from the wall to determine the appropriate route for running the cable across the service corridor and down into the tenant space. Employee #1 stepped onto a closed hatch door in the service corridor floor. The hatch door opened downward, and the employee fell approximately 13 feet, feet first, to the ground below. Emergency responders transported Employee #1 to Mercy Hospital, Folsom, CA. He was initially treated and then admitted for a total of three days hospitalization. He underwent surgery for a fracture to the right leg fibula, tibula, and ankle, and a fracture to the right wrist. At the time of this report, the employee had undergone two additional inpatient surgeries subsequent to the initial hospitalization, and he was receiving in-home health care support for ongoing treatment.