A fire that killed 10 people at a Massachusetts assisted-living facility was unintentionally caused by either someone smoking or an electrical issue with an oxygen machine, investigators said Tuesday.

Massachusetts fire marshal reports the Gabriel House fire that killed 10 and injured over 30 was accidental, possibly sparked by a resident smoking or a mechanical issue.

Ten people have died after a Massachusetts assisted living facility caught fire Sunday night, making elderly residents rush to their windows to scream and beg for help as smoke filled the hallways.

A new initiative focused on assisted living providers is launching today in Massachusetts in response to a fire that resulted in 10 deaths.

All 273 assisted living facilities in Massachusetts will be required to send a letter to all residents and families detailing fire safety protocols.

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.