YOUNGSTOWN — The National Transportation Safety Board announced Wednesday that it is headed to Youngstown to investigate the Tuesday afternoon explosion at the Realty Tower building downtown.

The NTSB announced the decision on X, formerly Twitter, saying its pipeline and hazardous materials division will investigate “Tuesday’s natural gas explosion in downtown Youngstown.”

The team was scheduled to arrive in Youngstown on Wednesday.

According to the NTSB website, its “Office of Railroad, Pipeline and Hazardous Materials investigates accidents involving railroads, pipelines and the transportation of hazardous materials.”

It investigates and issues safety recommendations to federal and state regulatory agencies, industry, safety standards organizations, carriers and pipeline operators, equipment and container manufacturers, producers and shippers of hazardous waste materials and emergency response organizations, the website states.

The office has been one of the lead investigators in the Norfolk-Southern train derailment in East last year.

It has four divisions, the railroad division, the pipeline and hazardous materials division, the system safety division and report development division.

The pipeline and hazardous materials division investigates accidents occurring during the transport of natural gas or other hazardous liquids, such as gasoline or propane, through pipeline systems and accidents in which public safety is threatened by the release hazardous substances, the website states.

The division investigates all pipeline accidents in which there is a fatality, substantial property damage or significant environmental impact,” it adds.

Youngstown Fire Chief Barry Finley and Mayor Jamael Tito Brown have said they will not discuss whether the explosion was caused by a natural gas explosion as many nonprofessionals have suggested, saying they will wait for the investigators to determine that.

As of Wednesday, the Ohio State Fire Marshal is the lead investigative agency, the mayor and fire chief said during a press conference.

First responders and others have said they heard a hissing sound after the explosion, suggesting a natural gas leak.

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