Abstract: At approximately 6:20 p.m. on October 23, 2012, Employee #1, a truck driver employed by International Surfacing Systems, was loading his truck's tank trailer with a mixture of half water and half oil. He determined that the truck exceeded the proper weight. He attempted to unload some of the mixture with help from Coworker #1, a plant assistant employed by the plant employer, Emultech. Employee #1 climbed up the ladder on the side of the tank and accessed the catwalk on top of the tank trailer. The catwalk did not have guardrails or other means of worker fall protection. Employee #1 was on the back end of the catwalk next to a crankshaft and hatch. He turned the crankshaft and opened the dome lid on the hatch to monitor the fluid level in the tank. He then began to close the hatch before descending from the tank. He lost his balance and fell approximately 10 feet 3 inches from the catwalk to the ground level along the right side of the tank trailer. Employee #1 required 2 days hospitalization and treatment for multiple fractures of the right foot and ankle and a fractured right kneecap. On October 23, 2012, the Kern County Fire Department reported this event to Cal/OSHA's Bakersfield District Office. International Surfacing Systems was primarily engaged in the manufacture, transport, and application of asphalt rubber for street maintenance. The site employer, Emultech, worked for the transportation division of International Surfacing Systems.