WASHINGTON -- Nine people are dead and dozens of others were hospitalized after a fire at an assisted living facility in Fall River in the US state of Massachusetts on Sunday night, according to the Fall River Fire Department.

During a Monday morning news conference, Fall River Fire Chief Jeffrey Bacon confirmed that nine people died and more than 30 people were taken to the hospital, including one with critical injuries.

"We had an unspeakable tragedy here in Fall River last night. Our thoughts and prayers are with the families of the victims. I'm prepared to tell you that nine people lost their lives in this building last night," Bacon said. "We have one in critical condition, but we had over 30 transported."

Firefighters responding to the Gabriel House on Oliver Street around 9:30 p.m. on Sunday local time (0130 GMT Monday) found heavy fire at the main entrance of the building, according to the Fall River Fire Department.

Five firefighters sustained minor injuries during the operation. There were about 70 residents inside the building.

A family center was established at St. Anne's Hospital to assist families in reuniting with loved ones.

Fire investigators from the Fall River Fire Department and the State Fire Marshal's Office are working to determine the cause of the fire.