A view of the latticework of rebar in the navigation lock's concrete floor. Crews needed to drill holes to secure the new concrete sill, but kept hitting the rebar that was threaded through the concrete below. Crews only had an approximate 15% success rate in drilling holes to the needed depth because of the varied rebar placement. A look inside the the cracks and damage to the concrete sill exposed and broken rebar inside the navigation lock's concrete. The damage to the navigation lock sill stopped water-borne commerce on the Columbia River for three weeks as crews worked to repair the damage.