Apparently, the WA DOT knew about damage to the bridge that collapsed last month. Damage has been noted as far back as 1979.
By the middle of last year, an inspector identified eight different points on the bridge that had high-load damage, including some portions in which components were deformed by the impact. Then, last fall, inspectors encountered perhaps the worst damage yet: A tall vehicle traveling northbound had struck the overhead bridge structure, ripping a 3-inch gash in the steel, causing three portions to distort and tearing off surrounding paint, according to images and documents obtained by The Associated Press under public records law.
Still DOT did not put a warning about the bridge on the permit, something they do with other low bridges. "That permit" refers to the permit for the load that hit the bridge.
That permit, however, was much different than another approval given just two days earlier to the same company. In that request, Mullen Trucking sought to bring a large boiler along Interstate 90, with a maximum height of just 14 feet. At 10 points on the route path, the DOT issued a "CAUTION" notice, detailing the height of the overhead clearance and asking the driver to take a different route if the load was within two inches of that level. None of those overhead heights were a problem on that specific permit because they were at least seven inches higher than the load.