1 killed, 7 injured after explosion at Chase bank in Youngstown, Ohio

One person has died and seven people were injured, including one critically, after an explosion rocked downtown Youngstown, Ohio, Tuesday, officials said.

The explosion occurred near Central Square Tuesday afternoon, police said.

It is unclear what caused the explosion, which impacted a building that contains a Chase bank and apartments, authorities said.

Youngstown Fire Chief Barry Finley had initially characterized the incident as a natural gas explosion, but later said crews were working to determine if there was a gas leak.

"All I know for sure is that there was an explosion," Finley told reporters during a press briefing Tuesday evening.

Mercy Health said Tuesday evening it is treating seven people who were injured in the incident, including one person in critical condition.

The body of a man who was an employee of the bank was pulled from the site early Wednesday morning, the fire chief said. Police were searching for his vehicle in the wake of the explosion, he said.

The floor collapsed into the basement, which was flooded, and search crews were working to send a mini-drone in there to aid in the search effort, Finley said.

The Chase bank is located on the ground floor of the building, with apartment units on the 12 floors above.

The building has been evacuated and streets in the surrounding area have been closed to traffic indefinitely due to the potential for a structural collapse, authorities said.

A Chase spokesperson told ABC News the company is in "close contact with local officials to check on the safety of everyone in the building and area."

"After that, we'll work to determine what happened and to assess the damage," the spokesperson said.

There is no evidence of any suspicious activity at this time, officials said.