MOUNT VERNON, Wash. — The National Transportation Safety Board (NTSB) has concluded its investigation into a bridge collapse caused last year by an oversized load from Canada, and found there was plenty of blame to go around.
The NTSB issued its findings today, noting a “series of deficiencies” resulted in the collapse of a Washington State bridge on May 23, 2013. The truck involved in the incident belonged to Alberta-based Mullen Trucking.
It has commissioned a US-based pilot truck firm to guide the oversized load to the Port of Vancouver, Wash. The load struck an overpass along I-5 crossing the Skagit River, causing the bridge to collapse and several vehicles to fall into the water below. No one was seriously injured.
The NTSB found the pilot/escort vehicle didn’t perform basic safety functions, Mullen failed to adequately plan its route and that Washington State’s permitting process was inadequate. It also noted there were too few low-clearance warning signs near the bridge.
The escort truck was equipped with a height pole, which one witness said struck several pieces of the bridge structure. The driver of the escort vehicle, however, was on the phone when the accident occurred and had made five calls using a hands-free mobile phone in the 30 minutes leading up to the incident.
The NTSB concluded the phone calls “diminished her ability to recognize whether the height pole struck the bridge.”
“Eliminating distraction in transportation is a top priority for the NTSB,” said acting chairman Christopher Hart. “As we can see from this accident, any element that reduces a driver’s attention can have harmful results. Drivers must always focus on the task at hand and be aware of their surroundings.”
Mullen obtained the appropriate permit for the truck, but failed to check and plan accordingly for low clearances along the way, the NTSB found. The truck was travelling in the right-hand lane, where the clearance was lowest. It would have cleared the bridge if it were travelling in the left lane, investigators found.
The NTSB called for changes in the permitting process used by Washington State, which would make carriers more responsible for route planning.
“This costly accident was the result of a series of mistakes that could have been avoided,” said Hart. “The recommendations issued by the NTSB highlight the importance of driver awareness and the states’ responsibilities to provide adequate resources about low clearances.”
The NTSB issued 18 safety recommendations. A complete list is available here.