Investigators continue to probe a Tempe mobile home blaze that claimed two lives and seriously injured three others.
Heavy fire was showing from the home as firefighters responded late Sunday night.
A man, woman and an 18-month-old were transported to a hospital with life-threatening injuries, according to Fox 10.
After the fire, crews found the bodies of a child and an adult.
Firefighters managed to prevent the fire from spreading to nearby mobile homes.
A neigbor said she had walked by the trailer with her dog about 30 minutes earlier and everything was OK.
"Smoke detectors really are the key to get the people out of a home safely," said Tempe Fire Medical Rescue Department Assistant Chief Andrea Glass. "Those are the biggest ways to get people out of the home and protect them from these types of fires. So we don't know if they were working or not. We have done smoke detector walks in this community, but I can't tell you if we had them working in this home, and we are investigating if this home had working smoke detectors."