Abstract: On April 26, 2004, Employee #1, a construction laborer was doing a job called mucking, that is, walking in wet concrete, spreading the concrete with a shovel to level it for cement finishers, when he was burned in the legs and ankles by curing concrete. The project being done was a light rail trolley line being built by Stacy and Witbeck Inc. in San Diego, CA. The job being done was a deep pour, which required employees to walk in the concrete to spread, vibrate and finish it. They were walking on a 3-inch rebar mat and the pour was 18-inches deep and 10-feet wide. When walking in the concrete, the surface of the wet concrete came to the calf area, below the knee, on most workers. Because of the unusual size of the pour and the hazards of walking in the concrete, the crew was given a pre-job meeting before the pour started and reminded to wear rubber rain boots over the shoes, to tape the boots closed to keep concrete out, and to wash immediately when their skin contacted wet concrete. The crew needed additional help so the general foreman called another crew and requested another laborer be sent to the pour site. This laborer, Employee #1, was inexperienced with the caustic burn hazard of wet concrete and did not arrive at the pour site until after the pre-job meeting had ended and the pour was underway. He attempted to enter the pour with normal work boots on, was stopped, given a used pair of rain boots belonging to another worker, and returned to the pour. Supervisors were involved in cement finishing and said they did not see what happened to the laborer after that. Employee #1 said his boots kept coming off and that he finally removed one boot and continued to work in the wet concrete, up to his calf. After four hours he reported his burn injury to the general foreman and left the site without washing off. A water hose was present about 100 feet from the pour area. Employee #1 said he was unaware of where the water hose was. He washed himself at home after he left. Employee #1 sustained third-degree burns to his right ankle and other areas of the lower legs and had 0.125- inch-deep sections of tissue debrided and replaced with grafts from his hip. He was hospitalized and remained in the burn unit for one week after surgery.