ST. LOUIS, MO/May 25, 2017 (STL.News) The federal investigation continues into the deadly explosion at the Loy Lange Box Company in south St. Louis in April.
On Thursday morning, members of the U.S. Chemical Safety Board held a news conference in downtown St. Louis, where they released an update into the investigation. The findings were presented through the CSB’s Factual Investigative Update report.
According to federal investigators, the explosion of the giant tank called a Semi-Closed Receiver (SCR) weighing nearly 2,000 pounds, stemmed from an earlier repair. Back in 2012, the tank was repaired for a leak. The contractor recommended that the bottom portion of the tank be replaced. Investigators say Loy Lange Box Company did not comply with that recommendation.
“An area of continuing interest surrounds a proposal received by Loy Lange 25 days after the repair was completed from the same contractor responsible for the leak repair work. The proposal suggested replacement of the entire bottom of the SCR to provide additional thickness in order to protect against corrosion. This replacement ultimately did not occur,” explains Cheryl MacKenzie, an investigation team lead with the U.S. Chemical Safety Board.
Fast forward to March 31, 2017. Investigators say employees at Loy Lange noticed another leak from the tank. Company officials contacted a service repair provider. A technician was scheduled to make the repairs on the next business day, Monday April 3, which was the same day as the explosion.
On Monday morning, the steam generation system was activated. Investigators say based on the start-up schedule typically followed by the engineers and the time of the incident, it appears that the “catastrophic failure” occurred near the end of the start-up process.
The investigation team has concluded that the vessel failed due to corrosion of the six inch ring. The thinness of the ring created a weakness, resulting in a piece of the tank to separate.
This resulted in a major blast, “equivalent to about 350 pounds of TNT” according to federal investigators. This launched the tank through the roof, crashing into the roof of neighboring business, Faultless Linen. Four people were killed in the explosion. One of the victims was an employee at Loy Lange Box Company and the three others were employees of Faultless Linen.
Another concern relates to the inspection process. Missouri requires repairs to comply with National Board standards, but the city of St. Louis has opted out of this requirement and operates its own code for inspections.
“The city of St. Louis has jurisdictional authority for Loy Lange Box Company and is responsible for annual inspections of the SCR. To date the CSB has not received evidence that any formal inspections of the SCR occurred.” MacKenzie said.
The Chemical Safety Board plans to release its final report later this year.