McNeilus explosion ruled an accident
A fire and explosion at McNeilus Truck and Manufacturing on Jan. 11 has been ruled an accident, according to a report released by the Minnesota state fire marshal.
The explosion, which occurred in a "paint baking room" in the truck manufacturing facility, injured six employees. According to the report by lead investigator Steve Wolf, no one was in the paint booth when the explosion occurred. An employee heard a noise, and commented that something "didn't look right." The employee then turned to walk away when the explosion happened.
Investigators found a leak in a truck's natural gas system. A hose had come undone, causing gas to leak. It remains unclear what caused the hose to come loose.
"It is further my opinion that the CNG (compressed natural gas) system that was located on
top of the refuse truck developed a leak and dumped the entire contents of the four cylinders of CNG into the room," the report stated. "Due to the downdraft air exchange system the air was removed and recirculated quickly and reached an explosive limit which was ignited by an unknown source."
The investigators do not believe that this was caused by human error, and the investigation was closed.
"There may need to be some new safety checks — including air monitoring, guidelines or procedures put into place regarding filling practices, or the use of CNG-fueled trucks in the facility in other stages of assembly prior to and including this line, but that is not my role in this investigation," Steve Wolf's report continued. "This was an unfortunate incident in any case, and the hope would be to learn and benefit from this so that this kind of event does not get repeated so no one has to go through this in the future."
McNeilus was fined $7,000 by OSHA in mid-July, the details of which have not yet been released.