MINNEAPOLIS (WCCO) – A federal agency's final report on the fatal Minnehaha Academy gas explosion says that the contractors hired to move the school's meters mistakenly thought a crucial valve was shut when it was actually open, spewing gas into the building as pipes were taken apart.
The National Transportation Safety Board released its final 10-page report Tuesday, detailing what happened before and after the Aug. 2, 2017, explosion. The blast killed two school employees, injured nine others and did an estimated $30 million in damage to the south Minneapolis private school.
According to the NTSB, the contractors, a father-son duo working for Master Mechanical Inc., believed the valve to one of the meters was closed because the "plug valve" was turned parallel to the pipes.
However, the valve was open, and as the pipes were being dismantled, workers in the building smelled gas and heard a "horrendous flow of air" coming from the basement. Just seconds after an announcement was made to evacuate, the building exploded.
The NTSB report says that the contractors had not completed the qualifications program required to do the necessary piping work. Also noted was a "lack of detailed documentation" that clearly laid out the scope of the project.
In a statement to WCCO, Master Mechanical says that it respects the findings of the report.
"Throughout this entire difficult time, we have cooperated fully with the NTSB," the statement said. "We continue to keep in our thoughts all those impacted by the incident."
According to the NTSB report, the service provider, CenterPoint Energy, did not have any workers on-site as the job was being performed. In the aftermath of the explosion, the utility changed its policies to require safety meetings between all parties involved ahead of work involving the relocation of gas meters. Other safety measures were also added.
In a statement Tuesday, CenterPoint Energy says it did not wait for the NTSB report to be completed to revamp its safety measures, adding that the company continues to be "fully committed to the safety of our employees, contractors, systems and the public."
A number of lawsuits have been filed in connection to the explosion, blaming CenterPoint Energy and Master Mechanical for not managing the meter relocation job with proper care.
On Tuesday, Minnehaha Academy released a statement on the NTSB report, saying that it makes clear that the school has no culpability in the explosion.
"Since this report relates to an open legal matter, we cannot comment further," the school's statement continued. "This process is being guided by our attorney so that our team can focus its full attention on our students."
Earlier this year, the school opened a student common area built on the section of the century-old campus destroyed in the explosion.
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