OLYMPIA, Wash. (AP) — Starting in the 1970s, Washington state bridge inspectors made note of evidence that large loads were clipping the Interstate 5 span that recently collapsed into the Skagit River.

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.

Even after that, state officials still didn’t take precautions to prevent truckers from doing it again.

The AP found that Washington state’s Department of Transportation regularly puts detailed warnings on its trucking permits when routes are projected to encounter potentially problematic areas of low clearance. But despite the history of issues on the Skagit River bridge, the state never added warnings to permits for that span.

Federal transportation investigators believe an oversized load struck the Skagit bridge last month, causing a portion of it to collapse into the river and two vehicles with it. Nobody was seriously injured, but the failure has continued to disrupt transportation along the crucial I-5 corridor between Seattle and Vancouver, British Columbia.