PAWTUCKET, R.I. (WPRI) — City officials are investigating after a construction collapse inside an old mill building that is being turned into apartments.

Three construction workers were hurt during the collapse, according to Acting Battalion Chief Michael Thurber, after part of the second floor collapsed into the basement.

The vacant mill is on the corner of Esten and Warren Avenues, behind the Hope Artiste Village.

Thurber said two men and a woman were pulled from the rubble and transported to the hospital. City spokesman Wilder Arboleda said one person was in critical condition, while the other two had minor injuries.

Firefighters initially were concerned there could be more workers trapped under the rubble, but after searching the building determined that everyone was out and accounted for.

The company that owns the mill building, Urban Smart Growth, said the injured employees worked for AD Contracting Services, a subcontractor of Metric Construction, the general contractor on the project.

“Our thoughts and prayers are with three injured employees,” Michael Gazdacko said. “All of us at Urban Smart Growth are concerned at what transpired earlier today, and we are working closely with the general contractor and government officials during their investigation. The architects, structural engineers, and safety consultants are at the site on a regular basis and are currently on-site to assess this issue.”

A person who answered the phone at Metric Construction said the company has no comment.

Ken Hoffa, a carpenter who was working inside the building with a different construction company, said he watched the floor collapse onto the workers.

“I was cutting up beams that were laying on the floor…100 feet behind me one of the beams that was holding up the third floor behind me actually came loose and broke, and fell, hitting the second floor causing the second floor to collapse,” Hoffa said.

He said he believed the beam that snapped was rotted, a common occurrence in an abandoned mill building. He said he didn’t blame human error for the accident, but still said he will not go back inside the mill when construction resumes.

“I’m worried, just for the fact that I have three children at home,” Hoffa said. “What scares me is it was so close to me.”

The collapse is being investigated by the Pawtucket Police, the city building official and OSHA. It’s unclear when construction might resume.

According to Urban Smart Growth’s website, the plan is to turn the five-story mill building into 149 loft style apartments, which will be connected to the Hope Artiste Village mill through sky-bridges.

The project has been approved for $3.6 million in state tax credits through the Rebuild Rhode Island program. A spokesperson for the Commerce Corporation said the credits won’t be awarded until after the project is finished, and then will be paid out over five years.