The Massachusetts State Fire Marshal revealed the possible causes of the fire that killed 10 people at an assisted living facility in Fall River.

The deadly fire at an assisted-living facility in Fall River, Massachusetts, was accidental, but the cause is classified as undetermined.

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.

The cause of a fire at a Massachusetts assisted-living facility that left 10 people dead remains undetermined for now as officials investigate whether smoking materials and an issue with a medical oxygen machine may have been factors,

Investigators reveal 2 possible causes of deadly fire at Fall River assisted-living home Investigators on Tuesday revealed new evidence linked to a raging fire that tore through an assisted-living facility in Fall River earlier this month, killing 10 people and leaving dozens of others hospitalized.

Investigators may never know for certain what sparked the fire on the left side of the U-shaped assisted living facility.

An investigation into the source of the fatal fire at a Massachusetts assisted living facility last week classified the cause as "undetermined," though officials believe it was an accidental ignition

The person who lived in the room where the fire began is among the 10 people killed, according to the state fire marshal

A survivor of the deadly fire at the Gabriel House assisted living home in Fall, River Massachusetts is now suing the owner.

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