After a section of a large industrial tunnel caved in, more than two dozen construction workers who were hundreds of feet below the streets of Los Angeles raced for miles in the

Workers were 400 feet (121 meters) underground and as much as 6 miles (9.6 kilometers) inside from the only entrance when the cave-in Wednesday evening threatened to trap them on the far side of the tunnel’s boring machine,

The tunnel, which is 18 feet wide and 7 miles long, is under the Wilmington neighborhood, a heavily industrial area filled with oil refineries slightly north of the Port of Los Angeles. The nearly $700 million project is designed to create space to carry treated wastewater to the Pacific Ocean.