WASHINGTON, D.C. — The National Transportation Safety Board (NTSB) has released its full report on the fatal 2010 Gray Summit, Mo., crash that involved a pickup truck, a truck-tractor and two school buses.
In late 2011, the NTSB called for a nationwide ban on driver use of nonemergency personal electronic devices while operating a motor vehicle after its meeting on the accident.
In the crash, a pickup truck ran into the back of a truck-tractor that had slowed due to an active construction zone. The pickup truck, in turn, was struck from behind by a school bus. That school bus was then hit by a second school bus that had been following. Two people died, and 38 others were injured in the incident.
The NTSB’s investigation revealed that the pickup driver sent and received 11 text messages in the 11 minutes preceding the accident.
NTSB determined that the probable cause of the initial collision was distraction, likely due to a text messaging conversation being conducted by the GMC pickup driver. The agency also found that the second collision, between the lead school bus and the pickup, was the result of the bus driver’s inattention to the forward roadway, and the final collision was due to the driver of the following school bus not maintaining the recommended minimum distance from the lead school bus.
Moreover, problems were found with each bus’ brakes. In terms of the lead bus, NTSB found that once power was restored to the bus and the engine was started, neither the ABS warning indicator nor the brake system warning indicator illuminated when the bus was running, and during deceleration testing. In the absence of power and with the engine off, the brakes functioned with manual hydraulic force only.
In addition, the brake lines that ran from the master cylinder to the hydraulic ABS unit appeared to be corroded and leaking, while corrosion was present on a few areas of other brake lines. When the brake pedal on the lead bus was depressed, the movement of the pedal was soft and spongy, and a brake fluid leak was observed in the brake lines running from the master cylinder to the ABS unit. Upon further examination, it was found that one of the bus’ brake lines had a 0.06- by 0.03-inch hole.
In regard to the second school bus, NTSB found that the company that owned the bus had fabricated a spring assembly to help return the brake pushrod from a braking actuation to its non-braking position in an attempt to turn off the service brake application indicator light on the dash. Inspection of the brake lines from the master cylinder to the wheels revealed corrosion in some locations.
