(Adds details on collapse and on pilot car)
By Jonathan Kaminsky
OLYMPIA, Wash. May 25 The oversize load on a
semi-trailer truck that struck a Washington state bridge was
likely too tall for the lowest point of clearance on the
structure, part of which collapsed after the collision, a
federal safety official said on Saturday.
Two vehicles behind the truck plunged into the frigid waters
of the Skagit River following the collapse of the span of
Interstate 5 on Thursday evening between the towns of Mount
Vernon and Burlington, about 55 miles (90 km) north of Seattle.
The three occupants of the vehicles were rescued from the
river, but activists and federal lawmakers seized on the partial
collapse of the steel truss bridge, which was built in 1955, to
call for greater investment in the nation's aging
But Washington state officials have said preliminary
indications were that the bridge, which was inspected twice last
year, was not structurally deficient and the section fell
because of the impact from the truck.
The truck was carrying on its flat bed a large steel,
box-like structure built to house drilling equipment, a
spokesman for the Washington State Patrol said on Friday.
The truck was permitted by the state to carry a load at a
height of 15 feet and 9 inches (4.6 metres), but the lowest
point of clearance on the bridge was 14 feet and 6 inches (4.1
metres), National Transportation Safety Board Chairman Deborah
Hersman told a news conference on Saturday.
The truck driver has told investigators he repeatedly
measured the height of his load at 15 feet, 9 inches, Hersman
said. She said the bridge was elliptical in shape, shorter on
the sides than in the middle, where the clearance was higher.
Hersman said NTSB investigators planned to measure the load
on a flat surface to confirm its height.
While the Washington state Department of Transportation gave
Alberta, Canada-based Mullen Trucking, the company that employs
the trucker, a permit to carry an oversize load at a height of
15 feet, 9 inches, the state does not provide operators with the
vertical limit of each bridge along a route, Hersman said.
The permit, a copy of which the state Department of
Transportation posted on its website, says the proposed route
for an oversize load "does not guarantee height clearances." A
state regulation also posted on the website makes clear the
operator is responsible for ensuring the route "is free of
As part of that obligation, the company must send a pilot
car through to check clearances along the route, Hersman said.
The driver of a pilot car with a pole measuring at least
the height of the oversize load did not radio the trucker to
warn about the span, Hersman said.
The truck driver has told investigators that his vehicle and
the pilot car were both traveling in the right lane, closer to
the shorter side of the bridge, as they crossed the span, she
said. At the same time, another commercial vehicle was traveling
in the left lane, where the clearance is higher, she said.
The steel structure the truck was carrying was damaged on
the top corner nearest the shortest clearance of the bridge,
David Postman, spokesman for Washington state Governor Jay
Inslee, said that with the incident still under investigation,
it was too soon to assess blame. "The governor has not pointed
the finger," Postman said.
Officials with Mullen Trucking could not be reached by phone
(Writing by Alex Dobuzinskis; Editing by Dan Whitcomb and Peter