Nine people were killed and at least 30 others injured late Sunday night after a fire tore through an assisted living facility in Fall River, Massachusetts, officials confirmed on Monday.

The blaze broke out around 9:50 p.m. at the Gabriel House Assisted Living Facility, located roughly 50 miles south of Boston. Fire Chief Jeffrey Bacon said crews managed to rescue at least a dozen residents as the flames quickly spread through the building, which housed about 70 people.

The fire escalated to a five-alarm response, with around 50 firefighters working to bring it under control, according to the Massachusetts Department of Fire Services.

Several victims were pronounced dead at the scene, while “many more” were rushed to nearby hospitals in varying conditions, the department said. Five firefighters were also injured but are expected to recover, as their injuries are not life-threatening.

Investigators from multiple agencies are working to determine how the fire started.