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,

The cause of a deadly fire​ at the Gabriel House assisted living home in Fall River, Massachusetts has been narrowed to two possibilities.

The fire began in a resident’s room in an assisted living facility in Fall River, where investigators found an oxygen machine and “smoking materials.”