Abstract: At 3:28 a.m. on October 24, 2012, Employee #1 was performing his duties as a scaffold erector for his employer, Brand Scaffold Services Inc. (Brand Energy & Infrastructure Services), a large industrial scaffold erection company. He was working to dismantle a scaffold inside a confined space, Reactor Vessel R-2833 at Chevron Refinery, a petroleum refinery in El Segundo, CA. The scaffold had been erected earlier for vessel inspectors and welders to access the inside walls of the vessel. After entering this top-entry vessel by climbing down a fixed ladder to the top of the interior scaffold, Employee #1 and Coworkers #1, #2, #3, and #4 proceeded to dismantle the scaffold to the bottom of the vessel, approximately 30 feet. When the dismantling was complete, Coworker #1 lowered a wire rope ladder instead of a fixed ladder to exit the vessel. Coworkers #2, #3, and #4 exited on the wire rope ladder while Employee #1 held the bottom of the wire rope ladder steady. Then Employee #1, who was not wearing fall protection, began his ascent. He climbed approximately 25 to 30 feet up the wire rope ladder but then suddenly lost control and fell to the bottom of the vessel. He required hospitalization for more than 30 days for treatment of leg, arm, and pelvic fractures.