Abstract: At about 3:30 a.m. on January 28th, 2011, an employee was working with two coworkers inside the carbon monoxide flue duct removing refractory. This accident site was an oil refinery that processes crude oil into saleable petroleum products. The turnaround work involved in the accident consisted of refractory removal inside a flue duct that was associated with the FCCU. The work crew was moved to a new confined space area in the Duct works because the refractory needed to be immediately removed at the location. The employer required the workers removing refractory to work within four feet of the leading edge associated with the 28 foot vertical fall hazard. Because of the heavy weight of the rivet buster, the work crew traded off using the tool until one got tired. The employee had finished using the rivet buster, and he handed the tool to a coworker. For an unknown reason, he walked the wrong direction into vertical flue duct section. The employee fell 28 feet onto a staging area. The employee's supervisor did not work in the permit confined with the workers. The employee and three coworkers were in a confined space adjacent to the fall hazard. All the employees, including the supervisor, required for all the permitted flue duct spaces to be "100 percent tie off". Nobody was tied-off, because no anchor points were established in the duct. The following factors contributed to the accident: 1) lack of barrier restricting the movement by the fall hazard at the duct, and 2) lack of fall protection for workers inside the duct as required by the confined space permit. The employee sustained a broken femur and compound fracture of his left arm.