LIVE OAK, Fla. — Autopsies showed three young children died of accidental asphyxiation when they became trapped in an unplugged chest-style freezer in their yard in north Florida.

Suwannee County Sheriff Sam St. John said there were no signs of trauma on the children, ages 1, 4 and 6. Their bodies were found Sunday at a home outside of Live Oak after they went missing while playing outside.

The Gainesville Sun reports two families lived at the home — a woman and her 4-year-old daughter, and the grandmother of the other two children.

St. John said the mother went inside while the children were playing on a trampoline. When she returned, they were gone. The children weren't breathing when they were found inside the freezer, which had a latch keeping them from opening it.