Federal investigators say the Maryland Transportation Authority failed to complete a recommended vulnerability assessment that would have shown the Francis Scott Key Bridge was at significant risk of collapse from a ship strike long before its demise last year.

Sixty-eight bridges across the US should be assessed to see if they are at risk of collapse if hit by a ship, transportation safety officials found, while urging the bridges’ owners to undertake immediate vulnerability assessments.

Wednesday will mark the 1-year anniversary of the Francis Scott Key Bridge collapse that killed 6 people, all part of a road maintenance team working on the bridge when it was hit by a ship.