NTSB: Minnehaha explosion occurred while moving a gas meter

The National Transportation Safety Board said the explosion at Minnehaha Academy’s Upper School occurred while crews were moving a gas meter.

The new information came during a press conference Thursday.

Christopher Hart, with the NTSB, said the organization is using the party process to investigate the incident.

The party process includes working with those involved in the accident, which helps provides expertise into what went wrong, Hart said.

Parties in the investigation include Minnehaha Academy, Center Point Energy, first responders and the Minnesota and Federal Office of Pipeline Safety.

The investigation will look at the operation of the pipeline system, how performance from maintenance crews could have impacted the explosion and emergency response.

The NTSB says they are on scene because their agency looks into natural gas explosions. In the last 5 years, they say they’ve investigated almost 20 natural gas explosions at similar structures. 

“Typically they involve considerable damage and fatalities as opposed to a pipeline explosion that is out in a rural area,” Hart said. 

Hart said after the investigation is completed, the board will issue safety recommendations to prevent future accidents.

Hart said the on scene investigation will begin Friday. He expects investigators will remain on scene for five to seven days.

“Our mission is to understand not only what happened, but more importantly, why it happened,” he said.
Hart said while on scene, the board will not determine the probable cause of the explosion.

While responding to questions from the media, Hart said he understood the explosion took place during the moving of a gas meter.

Hart expects another media briefing on Friday, but says this is an investigation that will last about a year.

The NTSB is an independent federal agency charged by congress to review aviation, railway, highway and pipeline accidents.