An Illinois girl died after a snow fort collapsed on her on Sunday while she played near her church.

The girl, whom the medical examiner's office identified as 12-year-old Esther Jung of Elk Grove Village, had dug up a fort with a nine-year-old girl in a snowbank near Rothem Church in Arlington Heights.

The girls were with their parents attending church services when they decided to go outside and play. After an hour had passed, and noticing that the girls had not returned, the parents went out to look for them. They found them buried under the snow and called for help.

The police said the snow fort had collapsed on both girls, and that the 12-year-old was in cardiac arrest and taken to the hospital, where she was pronounced dead shortly after.

The nine-year-old girl was treated for hypothermia. She is expected to survive.

It is unclear how the girls were trapped under the snow since there were no witnesses at the time of collapse.