Abstract: On November 11, 2009, Employee #1 was working as an insulation installer, which was his regular assigned job. On the day of the accident, Employee #1 was assigned by his supervisor to go with a coworker to the worksite, which was a music studio with several rooms. Employee #1 was told to fix insulation installed by the company a few weeks earlier. When Employee #1 and his coworker got to the worksite, the general contractor met them and told them to start in the drum room. The drum room was the first room on the left side, going to the back of the building. Employee #1 and the coworker both used a step ladder to look up into the ceiling area in the hallway, where two ceiling tiles had been removed. The coworker called the sales representative, who had been to the worksite, and asked him what specifically needed to be done. The sales representative indicated that they needed to fill in gaps in the insulation and tighten it. Employee #1 also talked to the sales representative. He indicated that there was no light in the ceiling area and that the job looked difficult, because he could not see where to go. Employee #1 used a six-foot step ladder to climb up into the ceiling. He crawled around on some pieces of plywood, which had been given to him by the contractor while fixing the insulation. At some point, Employee #1 crawled into an area where there was no drywall or hard ceiling, and he fell through the insulation, which was the only covering on T-bar. Employee #1 landed eight feet below on the wood floor, and he sustained fractures to his hip and vertebrae in his lower back. Employee #1 was hospitalized.