Abstract: At approximately 1:45 p.m. on July 22, 2013, Employee #1, employed by Caliber Interiors Inc., a drywall contractor, was working on the second floor of a commercial building. He was trying to pick up a plywood sheet measuring 8 feet by 4 feet from the floor. As he stepped forward to get a better grip on the plywood, he fell through an opening under the plywood. The opening measured 32 inches by 26.75 inches. Employee #1 fell from the second floor to the first floor, a height of 20 feet. Emergency services were immediately called, and Employee #1 was transported by ambulance to Riverside Community Hospital. He was admitted and treated for serious unspecified injuries. He remained hospitalized for approximately 1.5 months. The employer reported this incident to Cal/OSHA at 2:05 p.m. on July 24, 2013. Cal/OSHA initiated an investigation at 2:00 p.m. on July 25, 2013. The investigation determined that the employer employed 200 employees, including Employee #1, who was a regular full-time employee. The employer was not unionized.