Assisted living centers are rare in Mass, but many families still don’t know what they offer or how they differ from other elder care facilities.

Nine people have died after a Massachusetts assisted living facility caught fire Sunday night. The death toll was revised after an error from the district attorney’s office on Friday. Elderly residents rushed to their windows to scream and beg for help as smoke filled the hallways.

Brenda Cropper, 66, died at a hospital after being in critical condition all week after the fire erupted on Sunday, officials said.