MINNEAPOLIS — A maintenance worker at a Minneapolis school that partially collapsed after an explosion earlier this month had smelled natural gas and used a radio to tell others to evacuate less than a minute before the blast, according to preliminary report released Monday by the National Transportation Safety Board.

Two longtime school employees died in the Aug. 2 collapse at Minnehaha Academy.

The preliminary report doesn’t identify the maintenance worker who urged people to evacuate, but the school identified him as Don DuBois, a Minnehaha Academy alum.

The NTSB report said DuBois heard the release of natural gas and smelled it. He went to the school basement where contractors had been working on moving a gas meter, then ran back up the stairs and used a hand-held radio to tell others there was gas in the building and to “evacuate immediately,” the report said.

DuBois also searched for other people as he ran upstairs, the report said.

Receptionist Ruth Berg, 47, and custodian John Carlson, 82, were killed when the building fell. Nine people were injured, including maintenance worker and soccer coach Bryan Duffey, who was critically hurt and still hospitalized Monday in satisfactory condition. According to local media reports, Duffey had a leg amputated.

The NTSB said the explosion happened as two contractors were installing new piping to move gas meters from the school’s basement to the building’s exterior. Monday’s report says two new meters mounted on a wall were ready for the new piping to be connected.

“While workers were removing the existing piping, a full-flow natural gas line at pressure was opened,” the preliminary report said. “The workers were unable to mitigate the release of the gas, so they evacuated the area.”

Earlier this month, the NTSB said a father-son team working for contractor Master Mechanical had been moving the meter for CenterPoint Energy as part of the gas company’s plan to move meters outside for easier access. Christopher Hart, an NTSB board member, said days after the explosion that investigators were seeking details about the relationship between the two companies, the process for contracts, and any oversight of workers.

“That’s a very hazardous operation and requires considerable planning and oversight to conduct that operation safely… and we want to find out all we can about how robust was that oversight process,” he said.

Those details were not part of Monday’s preliminary report.

Minnehaha Academy is a private Christian school serving students from pre-kindergarten to 12th grade. The blast affected the campus that houses the high school. Classes there will start two weeks late, on Sept. 5, said Sara Jacobson, executive director of institutional advancement.

Jacobson said the 360 students in the high school will be attending classes at another location. She said details are being finalized and will be announced later this week.

The elementary and middle school students are on a different campus and will start classes Wednesday as planned.

Jacobson said this year will be different, but administrators are convinced it will be an “exceptional year of learning … It’s not the building, it’s the people who are in it.”


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