Elderly residents – some in wheelchairs and some dependent on oxygen tanks – were blinded by deadly smoke as they tried to escape an assisted-living facility in Fall River, Massachusetts, which caught fire Sunday evening.

According to Fire Chief Jeffrey Bacon, the blaze started in a room on the second floor on the east side of the Gabriel House building, but details about the exact origin and cause are under investigation.

The Massachusetts assisted-living facility where a fatal fire killed nine people was caring for dozens of aging residents reliant on wheelchairs and oxygen tanks, but it lacked the safety measures and most of the staffing requirements that are commonplace in nursing homes.

Gabriel House was an assisted living residence, according to the state of Massachusetts. Here's how the state defines that

Assisted living centers are rare in Mass, but many families still don’t know what they offer — or what they don’t.

The 100-unit assisted-living facility that burned Sunday night, killing nine people so far, opened in 1999 in Fall River, Massachusetts. Some photos on its Facebook page show neat rooms but older-looking carpeting and furniture, and before the fire state inspectors had hit the facility with health and safety citations.

A fire at the Gabriel House assisted-living facility in Fall River, Massachusetts, has claimed its 10th victim. The blaze, which trapped residents and injured many, raises concerns about safety regulations in such facilities.

WBZ-TV 's I-Team has found Dennis Etzkorn, the owner of Gabriel House in Fall River, has legal controversies in his past.

Around 50 firefighters, including dozens who were off-duty, rushed to Gabriel House in downtown Fall River just before 10 p.m. local time Sunday.