Four people were killed Sunday morning when a hot air balloon crashed in Arizona, police said. 

The balloon came down around 7:50 a.m. local time in the desert area east of Sunshine Boulevard and Hanna Road, officials in Eloy said. Eloy is about 65 miles southeast of Phoenix.

One person was critically injured in the crash. There were five people on board at the time of the deadly crash, according to the Federal Aviation Administration (FAA).

The Eloy Police Department has not yet publicly identified the victims of Sunday’s crash.

Police in Eloy said they’re looking into the incident alongside the National Transportation Safety Board (NTSB) and the FAA to determine the cause of the deadly crash. Investigators were on scene examining the downed balloon, identified by the NTSB as a Cameron Balloons A160 aircraft, on Sunday.

“The preliminary information is that the balloon impacted desert terrain following an unspecified problem with its envelope,” an NTSB spokesperson said.

The aircraft will be brought to a secure facility for additional evaluation. 

Earlier this year, two people died and a girl was injured after the hot air balloon they were riding in caught fire near Mexico City. Five people died in 2021 after a hot air balloon crashed into power lines in Albuquerque, New Mexico.