Driver errors, poor planning blamed in Washington state bridge collapse
OLYMPIA, Wash. — Insufficient route planning, a distracted pilot driver and an inadequate permitting process by the state of Washington all played a part in last year's Interstate 5 bridge collapse north of Seattle, which sent two cars into a river, the National Transportation Safety Board said on Tuesday.
The board voted unanimously after a nearly two-hour hearing to issue a number of recommendations, including encouraging states to ban nonessential cellphone use by pilot car drivers and requiring better warnings of low-clearance bridges, as well as lane-specific guidance for bridge clearance.
Chris Hart, acting chairman of the four-member board, said the wide-ranging report provided by NTSB staff showed the “many missed opportunities to prevent this accident.”
Board member Mark Rosekind said the report showed “there were holes in every one of these slices of cheese.”
A section of the bridge fell into the water in May 2013 when a truck carrying a tall load hit the bridge in Mt. Vernon, about 60 miles north of Seattle. Two other vehicles fell into the Skagit River, and three people were rescued with minor injuries.
William Scott, who was driving the truck with the tall load for Mullen Trucking, told investigators a freight truck came up fast on his left. He said he drove to the bridge's right side, which had a lower vertical clearance than the center lane.
According to the investigation, Scott thought his load was 15 feet, 9 inches — about 2 inches shorter than it was. The top of the load collided with the far right side of the overhead truss structure.
The state Department of Transportation automatically issued Mullen Trucking an oversize-load permit over the Internet, without personnel review and without comparing the given dimensions to the proposed route, according to Tuesday's staff presentation.
The pilot vehicle's driver, Tammy Detray, told investigators the clearance pole mounted on her vehicle never struck the bridge. She also said she was using her cellphone on a hands-free device at the time of the accident.
“Her entire reason for being there was to protect the oversize vehicle and the vehicles that shared the roadway with her, and yet she jeopardized the safety of others because of a cellphone call,” board member Robert Sumwalt said.
Sumwalt asked staff whether the accident could have been avoided if Detray had notified Scott of the low clearance. He was told Scott was following Detray too closely to stop safely.