The Delaware Dept. of Transportation and its consulting engineers are rushing to build new foundations for a section of the I-495 bridge through Wilmington. On June 2, DelDOT closed the span, a key six-lane north-south throughway that carries an estimated 90,000 cars per day, after learning that four of 37 piers were out of vertical alignment by up to 4%. Current estimates place the temporary repair project at $20 million. DelDOT said on June 10 it hopes to have the link partially back in service by Labor Day.

A large pile of dirt stored adjacent to the bridge by Keogh Contracting, a local firm, may have been a contributing factor to the structure's shift, which made DelDOT's first priority to remove the dirt, according to Barry Benton, assistant director of bridges. The estimated 50,000 tons of dirt, at 300 ft long, 150 ft wide and 20 ft to 30 ft high, could have been compressing the soft soil—consisting mostly of organic sediment—upon which the bridge is built. DelDOT put the contractor's removal cost at $260,000. Keogh did not return calls for comment.