LOS ANGELES — All 31 construction workers who were far inside a huge industrial tunnel in Los Angeles made it to safety after a portion of it collapsed Wednesday evening, an outcome officials called a blessing after they initially feared much worse.
The cave-in apparently happened between the tunnel boring machine, 5 miles (8 kilometers) in from the only entrance, and the construction crew working 6 miles (9.6 kilometers) in, said Michael Chee, spokesperson for the Los Angeles County Sanitation Districts, which is in charge of the nearly $700 million project. The workers were about 400 feet (121 meters) underground.
The tunnel is being constructed almost entirely underneath public right-of-way. The structure is 18 feet (5.5 meters) wide and will be 7 miles (11.3 kilometers) long to carry treated wastewater from across Los Angeles County to the Pacific Ocean.
Firefighters said workers had to climb over 12 to 15 feet (3.6 meters to 4.5 meters) of fallen dirt and debris to reach the tunnel boring machine and then were transported back to the opening. Some people had to be pulled out.
''They had to make themselves out through and then rescuers actually came to them to assist them out,'' Fire Department Chief Ronnie Villanueva said.
Aerial footage showed workers being brought out of the tunnel in a yellow cage hoisted up by a crane. None had major injuries, authorities said.
The workers were operating the boring machine when the collapse occurred, said Robert Ferrante, chief engineer and general manager for the sanitation districts.
''A section that they have already built had squeezing ground and had a collapse, a partial collapse,'' he told reporters.