OLYMPIA, Wash. (AP) — 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 below, the National Transportation Safety Board said 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."
"Movement of oversized loads is a specialized operation that demands special precautions," he said. "What this investigation uncovered were multiple gaps in multiple systems."
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 after a truck carrying a tall load hit the bridge in Mount 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 actually 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.