SKAGIT COUNTY, Wash. — A semi-truck crash on the Interstate 5 bridge over the Skagit River Wednesday morning was a reminder of a disaster that occurred in the same spot over seven years ago, and how work to make Washington bridges safer is not finished.
Officials with the Washington State Department of Transportation (WSDOT) said they got the call at 4:14 a.m. Wednesday to respond from Tumwater and inspect the bridge after a semi-truck carrying liquid nitrogen crashed, spilling the substance onto the roadway.
Liquid nitrogen is said to be at 320 degrees below zero Fahrenheit. Officials said they were concerned that the steel, in both the concrete sections of the bridge and on the truss, would become brittle and break if exposed to the super cold temperatures.
The bridge was closed for several hours and reopened mid-morning after inspectors gave the thumbs up to do so.
Wednesday's crash into a barrier on the west side of the southbound lanes happened just a few hundred feet from a disaster on May 23, 2013, when a truck carrying an oversized load caused a section of the bridge to collapse.
Cars and people fell into the Skagit River below. No one was killed in the initial collision. But, Washington State Patrol Trooper Sean O'Connell was killed while directing traffic through a series of detours around the severed section of one of the country's busiest interstates.
The crash investigation concluded that the corner of the large load had caught the curved decorative archway on the bridge’s steel truss, causing the structure to fail and collapse into the river.
"We have done a whole program with our vertical clearance program to measure the vertical clearance of our structures," said Evan Grimm, with WSDOT’s bridge preservation operations.
The corners of the remaining steel trusses over the Skagit River are now squared off. The state is trying to make sure that bridges on routes that could encounter oversized loads are set to at least 16 feet and six inches.
Officials with WSDOT said there's a better, more reliable system to route oversized loads, but more work remains.
"Right now we don’t have enough preservation dollars to take on a lot of those projects. We do them as we can," said Mark Gaines, WSDOT's bridge and structures engineer. "There is a backlog of bridges that could benefit from something similar to what we did on the Skagit to eliminate the low clearance portal frames and restore clearance through the structures."
The collapsed steel truss on the Skagit River bridge was replaced with a concrete span, but other steel sections of the bridge remain, only this time with their corners squared off and that extra clearance.