Pennsylvania firefighters say a fire at a daycare center has killed five children; the youngest is under one-year-old.

Firefighters say the fire started at a home that also served as a 24-hour daycare facility in Erie, Pennsylvania.

Firefighters say they arrived early Sunday morning to find the home engulfed in flames.

A team of Erie police and fire investigators suspect an electrical overload may have caused the fire.

According to investigators, there was only one working smoke detector that was located in the attic.

Five children, ranging in age from just 8 months to 7-years-old, were killed, and the owner of the daycare was flown to a hospital for treatment.

A state inspection of the facility earlier this year noted the presence of ashes and cigarette or cigar butts, which are banned in childcare spaces.

But according to records, the provider had promised to make sure it would be cleaned up and remain that way.

Monday morning, Fire investigators are still working to confirm the cause of the fire.