Abstract: The incident occurred on 2/4/10 at approximately 12:45 hours while the three injured employees (E1, E2 and E3) were performing his duties of employment as a drywall installators with American Theatrical Drywall and Framing Inc dba Americn Theatrical Construction at a job site located at 450 North Atlantic Bl, Monterey Park, CA. American Theatrical Construction is a private, incorporated company that conducts framing and drywal linstallation operations in the construction of stage and motion picture theaters. On site operations incorporate the use of powered and manual tools including drills, saws and nail guns as well as scissor lifts and industrial trucks. E1, 2 and 3 have been employed at American Theatrical Construction for approximaterly 11 years, two years and one month respectively. At the time of the incident, E1, E2 and E3 were working inside of a building at the west side of the site installing light gage metal framing. E1 and E3 were both working on the ground removing extraneous pieces of the metal framing as well as cutting new pieces for E2 who was working from a scissor lift at a height of 17 feet 5 inches installing ceiling trusses. At the same time a foreman of Fitch Plastering Corporation of California, W1, was operating a Gradall model 534C-9 telescoping boom industrial truck serial number 0344487 on the west side of the building where the wall had not yet been framed. W1 was using the industrial truck to deliver scaffold components weighing in excess of 5600 lbs to other employees of Fitch Plastering located on the roof of the building. The telescopic boom of the industrial truck measured 30 feet 5 inches and was determined to be operating at an angle of 39 degress. W1 stated that as he was booming the industrial truck out when it began to rock forward possibly due to the failure of the right front tire. It then rocked backwards and forward again tipping over toward the front causing the load of scaffold components to slide off into the scissor lift being operated by E2 pushing it over toward the east. E2 was thrown to the ground and E1 and E3 were both struck by the falling scissor lift. The maximum load for the industrial truck was determined to be 4000 lbs and the truck was equipped with three foam-filled tires and one pnuematic tire that was measured to have 22 psi of pressure upon inspection. The vice president of American Theatrical was E1, E2 and E3's direct supervisor at the time of the inspection and was in the job site office at the time of the incident. Cal/OSHA has determined that the accident was caused by the Gradall industrial truck being loaded beyond its rated capacity causing it to fall forward while delivering the load of scaffold components. A serious accident-related citation under title 8 section 3650(t)(26) will be issued to Fitch Plastering Corporation of California regarding the incident.