LIVE OAK, Fla. — Playing outside Sunday afternoon in a small north Florida town, three children got trapped inside a freezer and died.

According to the Suwannee County (Fla.) Sheriff’s Office, the three children — ages 1, 4 and 6 — were playing in their yard and, for unknown reasons, climbed inside a chest freezer when the adult watching them went inside the house to use the restroom.

The sheriff’s office is still conducting its investigation, but foul play is not suspected.

“It’s just really, really heartbreaking,” Sheriff Sam St. John said. “I really believe it was an accident, just a really horrific, terrible accident.”

According to the report, when the adult returned outside and couldn’t find the children, she awoke another adult at the house and they began searching the property and an adjacent vacant home.

They found the children not breathing inside the freezer, which was not plugged in, and began resuscitative efforts while calling 911.

When Suwannee County Fire Rescue and SCSO deputies arrived on scene, the adults were still performing CPR on the children, who were then transported to an area hospital.

Resuscitation efforts were not successful.

“It took an extended amount of time to find them and by the time they did, it was too late,” St. John said.

According to documents obtained by the Suwanee Democrat, a hasp had been installed on the lid of the freezer in order to be padlocked and authorities believe that when the lid closed, the hasp fell shut which trapped the children inside.

There was no padlock on the freezer.

The sheriff’s office said the case will be forwarded to the Third Judicial Circuit State Attorney’s Office for review and the Florida Department of Children and Families has also been notified.