A crowd of Los Angeles Unified School District teachers and Service Employees International Union 99 members gather in Grand Park outside of City Hall on Wednesday. About 150 of the district’s more than 1,000 schools remained open during the strike and had adult supervision but no instruction. Francine Orr/Los Angeles Times via AP

LOS ANGELES — Thousands of service workers backed by teachers began a three-day strike against the Los Angeles Unified School District on Tuesday, shutting down education for a half-million students in the nation’s second-largest school system.

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, walked out amid stalled contract talks.

Teachers joined rain-soaked picket lines early Tuesday as the striking workers demanded better wages and increased staffing before heading to a rally outside the district’s headquarters in downtown Los Angeles. 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. Nearly three-quarters are Latino.

Liev Kaplan, 6, marched with his mom, Tiffany, an adaptive physical education teacher. “We want to fight for everyone so they can have fair pay,” the first-grader said. His dad teaches math. “We are an education family,” Tiffany Kaplan said. “But we can’t educate if the kids are not fed, if they’re not feeling safe. We have to support our support staff.”

Lydia Vasquez searched for her husband in the crowd as demonstrators chanted “we are the future.” He works as a school custodian and she couldn’t remember the last time he got a raise. “We really need to be out here having our voices heard,” she said.

Leaders of United Teachers Los Angeles, the union representing 35,000 educators, counselors and other staff, earlier pledged solidarity with the strikers.

“These are the co-workers that are the lowest-paid workers in our schools and we cannot stand idly by as we consistently see them disrespected and mistreated by this district,” UTLA President Cecily Myart-Cruz told a news conference.

Myart-Cruz was joined by U.S. Rep. Adam Schiff, a Democrat and Senate candidate, who said the strikers were earning “poverty wages.”

“People with some of the most important responsibilities in our schools should not have to live in poverty,” Schiff said.

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 remained 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.

Teacher Sarah Harris joins Los Angeles Unified School District teachers and Service Employees International Union 99 outside the Edward R. Roybal Learning Center in as they strike on Tuesday. Damian Dovarganes/Associated Press

“I will make sure the wellbeing of L.A. students always comes first as I continue to work with all parties to reach an agreement to reopen the schools and guarantee fair treatment of all LAUSD workers,” Mayor Karen Bass said in a statement.

Jerilyn Lopez Mendoza said she supports the walkout because she wants staff to be compensated fairly, but she is worried about how missing three days of school will affect her 15-year-old daughter, who is autistic. For the sophomore it means three days away from her social circle and the routine that school provides, her mom said.

“I’m obviously in favor of the strike and want to be supportive of the workers and their requests for fair pay and working conditions, but it also does affect my family negatively,” Lopez Mendoza said.

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

Instructional aide Marlee Ostrow, who planned to join picket lines, 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.

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 Los Angeles 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.

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