A fire at a Pennsylvania day care has reportedly killed five children and sent the center’s owner to the hospital.

According to Erie Chief Fire Inspector John Widomski, the fire was reported at a single-family residence in Erie, Pennsylvania, at around 1:15 am Sunday (August 11). The victims names have not yet been released, however they reportedly ranged in age from eight months to seven years.

At least four of the five children who perished in the fire were siblings, according to Go Erie. The facility is a 24-hour day care called Harris Family Daycare. The center’s owner, Elaine Harris, was taken to the hospital for treatment of burns and is reportedly in stable condition.

A neighbor of the day care told Go Erie two children, aged 12 and 17 years old, managed to escape the fire by climbing out onto the first-floor roof and then jumping to the ground.

Investigators say the fire appeared to have started in the front living room area of the first floor of the facility.

Valeria Lockett-Slupski told Go Erie four of her grandchildren, two boys and two girls, were among the children who died in the fire. She says the kids’ parents had left them at the day care overnight because they were working a night shift and had been using Harris Family Daycare for almost a year.

“So we are all at a loss, trying to figure out how this happened,” Lockett-Slupski said.

Go Erie reports Pennsylvania Department of Human Services records show the day care was registered and compliant following a December 2018 inspection, with a certificate of compliance covering March 21 to March 2020.

The inspection, conducted on January 3 inspection, did reveal a presence of “ashes and cigarette or cigar butts,” which are banned in childcare and play spaces, according to CBS News.

Authorities are working to determine a cause for the fire.