On April 15th, 2021, officials, engineers, and even students gathered to christen “Rachel.” Rachel is a tunnel boring machine beginning her seven miles journey beneath Los Angeles. The Clearwater Projects held competitions with local school children to name and paint the machine. Then they lowered it down a 400 foot shaft to begin its journey, its crew celebrated like astronauts. No one could have known that four years later, families would be gathered by the same shaft hoping a brutal cave-in hadn’t killed the entire crew.

On Wednesday night, the city of Los Angeles announced the clearwater tunnel had collapsed. The tunnel, zig-zagging beneath the city to connect a wastewater treatment plant in Carson with the ocean, was six miles long when the roof caved in.

The three Orozco brothers were construction workers on the same tunneling shift, trapped underground together. Their sister, Arally Orozco told AP News (in Spanish) “It was sad and scary…We feared the worst.”

An hour later, she received a phone call. “My brother was crying…He told me he thought he was going to die underground.”

But all 31 construction workers had managed to squeeze through a tight space in the debris and meet rescue workers. They reportedly had to climb a pile of loose soil that filled 12-15 feet of the 18-foot-tall tunnel. News footage shows the rescue crew lifting the men up the 400 foot shaft in a yellow cage hanging from a crane. None of them suffered major injuries. You can see that footage below:

Did Los Angeles’ tunnel boring machine fail?

Los Angeles was using “Rachel” a tunnel boring machine built by Herrenknecht of Germany to drill seven miles from a Carson wastewater treatment plant to the Pacific Ocean. Preliminary reports say the tunnel machine was working on mile six and well past the collapse at mile five. The collapse occured beneath Los Angeles’ Wilmington neighborhood.

The tunnel boring machine includes a cutting head and 800 feet of “trailing equipment” that follows along on train tracks the crew build. This equipment includes ventilation and other life support for the crew, as well as the equipment for the tunneling machine itself. But even the trailing equipment may have been past the collapse point. You can learn more about Clearwater Tunnel Project and its tunnel boring machine in the video below: