Abstract: At 1:00 p.m. on May 13, 2021, an employee was working as a truck driver for a company that provides support services for oil and gas companies. The employee was working on a crew with four coworkers that had been subcontracted to replace the fire tubes on a heater treater and clean the inside of the tank. Three coworkers who were employed by a construction group were contracted as a roustabout crew to conduct the work. Another coworker from the same company as the employee was contracted to operate the vacuum truck and suck the sludge out of the tank. Another contractor was hired to operate a hot oil truck to provide water to the roustabout crew for cleaning. The crew had completed pulling out the old fire tubes and had begun the process of cleaning the inside of the tank when an explosion occurred. The employee was hospitalized to treat 2nd and 3rd degree burns to his upper body including his face and arms.