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.

A former employee said she never saw the staff perform fire drills. The local fire chief pushed back at claims that dispatching more firefighters would’ve saved more lives.

More than 75 percent of Gabriel House residents are enrolled in Medicaid, state officials have said, and it charges significantly less than a typical assisted living facility does for private-paying patients.