The incident occurred on Monday, April 3, when the tank, a semi-closed receiver (SCR) exploded through the roof and flew approximately 500 feet into the air before crashing into Faultless Healthcare Linen Company, a medical laundry business.
US Chemical Safety Board
The blast initially killed one person, engineer Kenneth Trentham, 59, at Loy-Lange Box Co. and two others at Faultless Healthcare Linen Company. A fourth person died from their injuries at St. Louis University Hospital, according to Rosa Psara St. Louis county chief medical examiner.
The two people killed by the large debris were reportedly on their first day of the job at Faultless Healthcare Linen Company.
According to the US Chemical Safety Board (CSB) both Loy-Lange Box Co. and the Faultless Linen office that were affected by the explosion are too dangerous to inspect.
"The SCR tank was part of a steam generator that serves the same purpose as a boiler, but is of a different design," a CSB spokesman said.
The board's report said investigators do not know why the tank failed. The structural issues at Faultless Linen make it "too dangerous to enter the room to conduct an in-depth examination," it said.
It is unclear what caused the explosion and whether someone was working on the tank at the time of the incident. Foul play is not suspected.
“The CSB’s mission is to investigate and issue recommendations that promote safety at industrial facilities as well as for nearby communities. As a result of Monday’s explosion, our team will be examining what if any safeguards were in place to protect the workers at the Loy-Lange Box Company, as well as for those in the adjoining building,” added Vanessa Sutherland, chairwoman, CSB.
The CSB is an independent federal agency whose mission is to drive chemical safety change through independent investigations to protect people and the environment. CSB investigations look into all aspects of chemical incidents, including physical causes such as equipment failure as well as inadequacies in regulations, industry standards, and safety management systems.
Loy Lange Box Company founded in 1897, makes corrugated boxes, POP (Point of Purchase) and pallet displays for the food and beverage industry among others.
The cause of the explosion is under investigation by St. Louis Fire Department and the US Occupational Safety and Health Administration.