NTSB says school explosion probe could take year

MINNEAPOLIS — Workers might have been moving a gas meter when an explosion tore through a Minneapolis school building this week, killing two people and injuring at least nine others, according to federal investigators who arrived Thursday.

A team from the National Transportation Safety Board was in Minneapolis to begin the painstaking task of determining what caused Wednesday’s natural gas explosion at Minnehaha Academy. The bodies of two school workers — longtime receptionist Ruth Berg and custodian John Carlson — were found in the rubble.

Investigators will look into the movement of the gas meter, as well as whether the gas was turned off inside the building or at the street as the work was being done, NTSB board member Christopher Hart said. The NTSB is investigating because it has jurisdiction over gas pipelines.

Hart said investigators will be on site for up to seven days as they document the evidence but that it could take a year for the agency to finish its work and issue safety recommendations.

“Our mission is to understand not only what happened, but more importantly, why it happened, so that we can make recommendations to prevent it from happening again,” Hart said.

City fire officials have said the explosion happened in a utility area at the private Christian school, which serves students ranging from pre-kindergarten to 12th grade. The blast occurred while students were on campus playing soccer and basketball, according to fire and school officials.

Aerial video footage shows that part of a building was ripped apart, with wood splintered and bricks scattered about. Windows in other areas, including classrooms, were blown out.

Contractors were working in the school at the time, and some witnesses said they were warned of a gas leak moments before the blast. Some first responders also reported smelling natural gas as they pulled people to safety.