A small plane crashed in Wyoming’s Bighorn National Forest on Monday, killing a 13-year-old girl and seriously injuring three of her relatives — an 11-year-old boy and two adults.

Rescue teams located the downed single-engine aircraft near Big Mountain and airlifted the survivors to hospitals.

Authorities said the FAA is investigating the crash, and the sheriff’s office has asked the public to avoid the area, ABC News has reported.