(FALL RIVER, Mass.) -- Nine people have been killed and dozens are hurt after a five-alarm fire tore through an assisted-living facility in Fall River, Massachusetts, officials said.
Firefighters, police and other responders descended on the scene of the Sunday night fire at the Gabriel House assisted-living facility, where they found multiple people "hanging out of the windows, screaming and begging to be rescued," Fall River Fire Chief Jeffrey Bacon said.
The front of the building was covered in heavy smoke and flames, Bristol County District Attorney Thomas Quinn III said.
"This was not a situation where teams arrived and people were able to get out easily -- all of these people needed assistance," Massachusetts Gov. Maura Healey said. "Many were in wheelchairs, many were immobile, many had oxygen tanks."
About 12 "non-ambulatory residents were physically carried out by our officers," according to Fall River police.
Thirty people, including five firefighters, were taken to local hospitals, Bacon said. One person is in critical condition, Bacon said. The five firefighters have already been released, officials said.
One resident told reporters that he was in his room on Sunday when a first responder told him he had to evacuate immediately.
"I had my oxygen tank hooked on ... I get my charger for it, my wallet," he said. "I went to my room door, I opened it and all the smoke from the hall went right in my face."
"I thought it was gonna be the end of everything," he said.
The resident said he couldn't see anything in front of him through the smoke.
Two responders helped him down the stairs, he said, adding, "I just tried to do my best not to fall."
After two residents told The Associates Press that staff members fled the building without telling residents about the fire, Bacon told ABC News Live, "That's certainly something that we need to look into."
The facility "would have had to have had an approved fire evacuation plan," including fire drills, "so that's definitely something that ... will be exposed, if it did happen, to our investigation," he said.
Resident Lorraine Ferrara told the AP that two staff members "left us alone and ran out into the parking lot."
The building -- which was home to about 70 people -- is now clear, officials said.
The DA said the residents killed were: 64-year-old Rui Albernaz, 61-year-old Ronald Codega, 69-year-old Margaret Duddy, 78-year-old Robert King, 71-year-old Kim Mackin, 78-year-old Richard Rochon, 86-year-old Eleanor Willett. The names of the other two victims -- a 70-year-old woman and a 77-year-old man -- have not been released.
At a news conference, the governor expressed her gratitude for the first responders' quick actions.
"Were it not for that, we would've seen an even far -- an unimaginable loss of life here, given the vulnerability of this population," she said.
The cause of the fire is under investigation. The district attorney said "the cause does not appear to be suspicious."
One official briefed on the probe told ABC News that, as a preliminary matter, the fire does not appear to have been set intentionally. More likely, the source said, it appears to have been caused by some sort of electrical or mechanical problem.
Meanwhile, union leaders are calling out what they say is a long-standing failure to adequately staff the city's fire department.
"What happened last night was not only a tragedy for the city of Fall River, it was a travesty," said Edward Kelly, general president of the International Association of Fire Fighters. "Had the Fall River Fire Department been staffed to national standards, lives would have been saved."
Kelly, speaking on behalf of the IAFF's members across the U.S. and Canada, said only two of the department's 10 fire companies are staffed with the national standard of four firefighters. He said the remaining eight operate with just three.
"If all companies had been properly staffed, there would have been eight more firefighters on the scene. Eight more people who could have been making rescues. That could have made the difference," Kelly said.
Despite the challenges, Kelly praised the firefighters who responded. He said some rushed in off duty, without proper protective gear or breathing apparatuses.
"They kicked in doors, they carried people out, they risked their lives," he said. "But it wasn't enough -- and that's not their fault. It's the fault of the system that failed them."
Michael O'Reilly, president of the Fall River firefighters union, said the fire exposed what he called the consequences of treating public safety as "a line item in a budget."
"Forty minutes into this fire, my brother, Capt. Frank O'Regan, arrived off duty and went in alone," O'Reilly said. "He ventilated windows, searched rooms and found three victims. There were no other firefighters available to help him search the rest of the building. That's unacceptable."
Fall River, near the Massachusetts-Rhode Island border, is about 50 miles south of Boston.
The burned building was built in 1964 and underwent an exterior remodeling in 2000, according to tax assessment records. It was listed on the assessment form used by the city as having an "average-good" physical condition as of this February, the records said.
ABC News' Jared Kofsky, Matt Foster, Jason Volack and Jessica Gorman contributed to this report.