BOSTON (AP/WHDH) — The Occupational Safety and Health Administration says it’s opening an investigation into each of the three companies involved in a South Boston construction site that injured three workers, including one whose legs were trapped under a wall for hours.

The investigation into Suffolk Construction, Northstar Contracting Group, Inc and TRC Companies could take up to six months.

Firefighters in Boston worked for more than three hours to rescue an injured construction worker after part of a historic power plant collapsed Wednesday while being redeveloped.

Fire Commissioner Jack Dempsey told reporters the worker sustained life-threatening injuries when a wall collapsed and landed on his legs and lower body.

Two other workers were quickly removed from the former Edison Power Plant in South Boston and taken to an area hospital with non-life-threatening injuries, he said. The collapse occurred at around 1:45 p.m.

Wednesday’s incident was the second collapse at a Boston construction site this year. A construction worker died in March when a part of a parking garage being demolished collapsed.

“It’s a reminder that every large construction site carries tremendous risks for the workers,” Mayor Michelle Wu said. “Every worker, every family member of workers across our city, need to know that it cannot be a question whether your family member will come home at night.”

The plant, which is over 120 years old, is being redeveloped into a mixed-use property that includes residential, office, research and retail space, a hotel, and open public space, according to the Boston Planning and Development Agency.

The federal Occupational Safety and Health Administration was also investigating, a spokesperson said.

Suffolk Construction, the company responsible for the deconstruction, said a catwalk had collapsed at the building, which is more than 120 years old. “We are currently on site working closely with OSHA, our subcontractor and the local authorities to determine the cause of this incident and confirm the safety of the site,” the company said in a statement.

Hilco Redevelopment Partners, which is developing the site, thanked first responders for their quick actions.

The collapse remains under investigation.

(Copyright (c) 2022 Sunbeam Television. The Associated Press contributed to this report. All Rights Reserved. This material may not be published, broadcast, rewritten, or redistributed.)

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