Three people are dead and one is injured after a SUV veered off the road and crashed into a tree in south Alabama, according to police.

The single-vehicle crash happened about 6 a.m. Monday on Sam Avenue in Mount Vernon, about a mile east of Highway 43, according to the Mount Vernon Police Department.

Residents of the area told WKRG that they heard a loud explosion shortly before the crash.

According to officials, once the SUV hit the tree, it immediately caught on fire. Three people were confirmed dead, while the fourth was taken to an area hospital.

The injured person’s condition is currently unknown at this time.

Officials with the Mount Vernon Police Department are still investigating the incident.