Abstract: At 2:30 a.m. on April 23, 2008, hot oil (400 degrees F) was being drained from the "Rundown" pump and into the sewer system, at the coker unit of a refinery in Tyler, Texas. In this routine task, oil was drained prior to cleaning a suction screen, before switching from one coker drum to another. The task was done every 18 hours to 24 hours and had been done since the coker unit was built in 1979. The sewer, which was also built in 1979, was contained inside the refinery to control spills of industrial materials. Pumps were drained into the sewer throughout the refinery. As the hot oil was draining, it spewed out of the drain and drenched Employees #1, #2, and #3. The employees sustained second degree burns to their arms, abdomens, and faces, and all three were hospitalized overnight.