Tens of thousands of workers in the Los Angeles Unified School District walked off the job Tuesday over stalled contract talks, and they are being joined in solidarity by teachers in a three-day strike that has shut down the nation’s second-largest school system.

Demonstrations began at a bus yard and are expected at schools across the city by members of Local 99 of the Service Employees International Union, which represents about 30,000 teachers’ aides, special education assistants, bus drivers, custodians, cafeteria workers and other support staff.

The workers joined picket lines in a steady rain before dawn, demanding better wages and increased staffing. Some held signs that read “We keep schools safe, Respect Us!” The district has more than 500,000 students from Los Angeles and all or part of 25 other cities and unincorporated county areas.

Superintendent Alberto M. Carvalho accused the union of refusing to negotiate and said that he was prepared to meet at any time day or night. He said Monday a “golden opportunity” to make progress was lost.

“I believe this strike could have been avoided. But it cannot be avoided without individuals actually speaking to one another,” he said.

Local 99 said Monday evening that it was in discussions with state labor regulators over allegations that the district engaged in misconduct that has impeded the rights of workers to engage in legally protected union-related activities.

“We want to be clear that we are not in negotiations with LAUSD,” the union said in a statement. “We continue to be engaged in the impasse process with the state.”

Those talks would not avoid a walkout, the statement said.

During the strike, about 150 of the district’s more than 1,000 schools are expected to remain open with adult supervision but no instruction, to give students somewhere to go. Dozens of libraries and parks, plus some “grab and go” spots for students to get lunches also planned to be open to kids to lessen the strain on parents now scrambling to find care.

“Schools are so much more than centers of education — they are a safety net for hundreds of thousands of Los Angeles families,” Los Angeles Mayor Karen Bass said in a statement Monday. “We will make sure to do all we can to provide resources needed by the families of our city.”

Workers, meanwhile, said striking was the only option they had left.

Instructional aide Marlee Ostrow, who supports the strike, said she’s long overdue for a raise. The 67-year-old was hired nearly two decades ago at $11.75 an hour, and today she makes about $16. That isn’t enough to keep pace with inflation and rising housing prices, she said, and meanwhile her duties have expanded from two classrooms to five.

Average Annual Salary of $25,000

Ostrow blames the district’s low wages for job vacancies that have piled up in recent years.

“There’s not even anybody applying because you can make more money starting at Burger King,” she said. “A lot of people really want to help kids, and they shouldn’t be penalized for wanting that to be their life’s work.”

The union says district support staffers earn, on average, about $25,000 per year and many live in poverty because of low pay or limited work hours while struggling with inflation and the high cost of housing in LA County. The union is asking for a 30% raise. Teachers want a 20% pay hike over two years.

Carvalho said the district has offered a wage increase totaling more than 20% over a multiyear period, along with a 3% bonus. In addition, the deal would include a “massive expansion of healthcare benefits,” the superintendent told Fox 11 on Monday.

The strike has wide support among union members.

SEIU members have been working without a contract since June 2020, while the contract for teachers expired in June 2022. The unions decided last week to stop accepting extensions to their contracts.

United Teachers Los Angeles, the union representing 35,000 educators, counselors, nurses and other staff, expressed solidarity with their striking co-workers.

“Educators will be joining our union siblings on the picket lines,” a UTLA tweet said. The teachers’ union is also bargaining with the district.

Teachers waged a six-day strike in 2019 over pay and contract issues but schools remained open.