Semi Truck Rolls Backward into Bus

A dump truck crushed a bus behind it.
A dump truck was climbing a hill when its engine suddenly died. This caused the truck to loose power in its air brakes which led to the dump truck rolling backwards. The dump truck continued backwards until crashing into a school bus. Seven people were rushed to the hospital. By the time the dump truck driver had been able to restart his engine and reactivate the air brakes, he had already slammed into the bus located behind the truck.