Abstract: Employee #1 was fatally injured while delivering a load of saw dust when the tractor trailer truck he was operating rolled backwards on a 6 degree inclined road and went through a retaining barrier and onto a 24 degree hill. The tractor and trailer left the roadway and rolled onto its left side and continued down the hill on its side until reaching the bottom of the hill at which time it rolled onto its top. The tractor and trailer came to rest inverted. The trailer's brakes failed 3 minutes and 35 seconds after being applied. The brake airlines then back-fed into the tractor's brake reservoir causing the tractor's brakes to release. The brake failure combined, along with the vehicle being on an incline and being approximately 16,000 pounds over design weight contributed to the rig rolling backwards off of the road. Employee #1 was killed.