At approximately 12:10 p.m. on January 21, 2014, Employee #1, Employee #2, a 36-year-old male, and a coworker, a 39-year-old male with a truck washing business, were engaged in cleaning out the interior of the tanker trailer. The equipment involved was a 6,500-gallon tanker trailer which was pulled in for interior cleaning. This tanker trailer was manufactured in May 1991. The cleaning process involved recycled water pumped from settling ponds on the property. Work was being conducted by two shifts, a day and evening shift. Each shift consisted of four workers and a supervisor. Employee #1 was working alone with no attendant. The supervisor pulled the tanker trailer in to the wash bay after it sat outside all night in sub-freezing temperatures.
The four-day shift workers were on morning break. The supervisor opened the man hatch located on top of the trailer and inserted the recycle water hose to start the initial rinse of the tanker. The supervisor opened the valves on the back of the tanker; they had frozen material in them. The supervisor then used a torch and hot water to remove the frozen materials. When the supervisor left the tanker trailer, water was flowing from the open, rear valves. When the workers returned to work, Employee #1 started to clean the tanker trailer.
