The cause of a fatal garbage truck wreck that occurred Tuesday in Valley Grande is still under investigation, according to the Dallas County Sheriff’s Department.

“The State Motor Carrier Inspector looked at the vehicle today,” Chief Deputy Randy Pugh said. “His full report will be ready in about a week.”

The accident occurred in the 700 block of North Lake Drive around 10:50 a.m. A preliminary report cited a mechanical malfunction as the cause of the crash. The driver of the garbage truck was taken to Vaughan Regional Medical Center for treatment, while the passenger died at the scene of the accident. Authorities have not released the victim’s name because family members have not received notification.

The driver told Dallas County Sheriff’s officials that the garbage truck’s brakes failed. Dallas County Sheriff’s Sgt. Mike Granthum said the driver attempted to slow the truck down by shifting, and when he pushed the brake it went to the floor. The driver and the passenger removed their seatbelts and jumped from the garbage truck before it hit trees about 160 feet from the road.

The Dallas County Sheriff’s Department is handling the investigation since the accident occurred on a private road.