Los Angeles ? Labor unrest caused even more anguish across Southern California on Wednesday as contract bus drivers walked off the job in solidarity with striking transit workers and two courthouses were temporarily shut down as the result of a separate dispute.

Meanwhile, 70,000 grocery clerks from three chains spent their fourth day on picket lines in the southern and central part of the state with no sign of a new contract. Grocery workers in four other states — West Virginia, Ohio, Kentucky, California and Missouri — are also on strike.

Nearly half of the 427 Los Angeles County sheriff’s deputies who work at jails and transport prisoners to court called in sick Wednesday, temporarily closing the Santa Monica and Beverly Hills courthouses, said Deputy Johnie Jones. Deputies have been protesting stalled labor talks with sporadic sickouts over the past three weeks, and many jails were on lockdown.

Assistant Sheriff Doyle Campbell said the department would begin suspending deputies who did not show up for work.

The three labor disputes have created a spate of problems across the region: Hundreds of thousands of commuters are stranded. Freeways are clogged. Grocery stores are scaling back hours. And the already ailing economy has taken a hit.

“Yesterday I couldn’t get to work,” Ginara Santay, 44, said as she waited for a ride Wednesday morning. Santay usually takes buses to four different house-cleaning jobs each week.

“Tomorrow I have no idea how I will get to work. I have an 8-year-old son. I’m worried about the rent. I can’t afford to miss one day, and I don’t know what I’m going to do.”

The strike against the Metropolitan Transportation Authority began Tuesday when mechanics walked off the job in a dispute over health benefits and other issues, shutting down the nation’s third-largest mass-transit system.

Some 2,000 MTA mechanics walked out, with another 6,000 bus drivers and clerks honoring the mechanics’ picket lines. On Wednesday, 250 employees of the company First Transit joined the strike.

Ron Garcia, center, and clerks for the Metropolitan Transportation Authority carry picket signs during a strike in Los Angeles. Mechanics for the nation's third-largest public transportation system went on strike Tuesday.