SAN FRANCISCO (CBS SF) — The Twin Peaks Tunnel, which takes San Francisco Municipal Railway riders between the city’s Castro and West Portal stations and beyond, will reopen Saturday, Muni officials announced.

With the reopening, full service will return for the K-Ingleside, L-Taraval and M-Ocean View lines. Service on the NX-Judah Express line will resume on Monday.

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The 100-year-old tunnel has been closed and under construction for the past two months.

Improvements to it include updates to the walls, tracks and drainage systems. Additionally, seismic reinforcements and fire safety enhancements have been added. Four track crossovers will also be installed to allow trains to switch tracks during delays, according to Muni officials.

“We are very thankful to our Muni riders, construction crews, neighbors, operators and” San Francisco Municipal Transportation Agency staff,” SFMTA Director of Transportation Ed Reiskin said in a statement.

“Your patience and dedication to this project means we all have new tracks and a safer more reliable Twin Peaks Tunnel for everyone to enjoy,” he said.

During the project, on Aug. 10, a falling steal beam struck construction worker Patrick Ricketts near the West Portal end of the tunnel and he was rushed to the hospital where he died. Ricketts, 51, was a resident of Colusa County and worked for Oakland-based Shimmick Construction.

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After Ricketts’ death, it was discovered that the construction company had a history of workplace and safety violations, including one involving a November 2016 fatality. In that incident, a worker operating a forklift died after losing control and going into a trench.

When applying for the Twin Peaks Tunnel construction job, Shimmick Construction reportedly checked “no” on documents that asked whether it had been cited for any serious and willful safety violations by the California Division of Occupational Safety and Health in the past ten years.

In a letter on Monday, Mayor London Breed wrote to Reiskin, saying, “I am seriously concerned about the lack of background checks performed on major construction contractors.”

SFMTA officials have maintained that Shimmick Construction met the requirements to pre-qualify for the bid.

Supervisor Norman Yee said last week he’s planning to hold a hearing next month to investigate how city contractors are chosen.

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