ELOY, Ariz. (AP) — Four people were killed and another critically injured after a hot air balloon crash Sunday morning near Eloy, Arizona, authorities said.

Eloy police said the crash occurred about 7:50 a.m. Sunday in a rural desert area about 60 miles (97 km) south of Phoenix.

The victims’ names are being withheld until their relatives can be notified, police said.

The National Transportation Safety Board and Federal Aviation Administration are investigating the cause of the fatal crash.