Thousands of Los Angeles teachers are about to go on strike. What will happen to 600,000 students?

Updated 0416 GMT (1216 HKT) January 10, 2019

(CNN)The country's second-biggest school district could see a mass exodus of teachers Monday when the Los Angeles teachers' union goes on strike.

Years of frustration over class sizes, salaries and a shortage of school counselors and nurses have boiled over for more than 30,000 members of United Teachers Los Angeles.
The Los Angeles Unified School District has made offers to try to prevent the walkout, but the teachers' union said they're not enough. So unless the warring sides find a solution fast, LA teachers will go on strike for the first time in 30 years.
UTLA President Alex Caputo-Pearl, center, joins teachers at a rally December 15, 2018 in Los Angeles.
"We want an agreement that works for our kids -- that gets to a place where we're not dealing with 50 kids in a classroom, where we're not dealing with 40% of our schools having a nurse for only one day a week," said Alex Caputo-Pearl, president of the UTLA union.
Despite the expected absences of 32,000 teachers and staff members, classes will continue at all schools. About 600,000 students could be taught by more than 2,000 reassigned administrators and about 400 substitute teachers, the school district said.
Exactly how that would work out logistically remains uncertain.
"It's case by case, school by school," said Shannon Haber, chief communications officer for LAUSD. "We're going to have to troubleshoot on the day of."
While the teachers' union acknowledged the impact of the upcoming strike on thousands of families, UTLA also invited families to join them on the picket lines.
"While every family will make their own decision on whether to send their child to school in the event of a strike, having many parents and allies on picket lines will be powerful and transformative," the union said.

What do both sides want?

Both the union and school district say they want smaller class sizes, bigger teacher salaries and more counselors and nurses in the district's roughly 1,000 schools.
The big debate revolves around how to fund them.
LAUSD says $1.8 billion in reserves is already earmarked for education spending.
Union members say they want LAUSD to pull from its $1.86 billion in reserves to increase school staffing and to boost teachers' salaries by 6.5%.
"We have been in negotiations with LAUSD since April 2017. We have been working without a contract for almost one year," UTLA said in a statement. "Even with $1.86 billion in reserves, LAUSD says it does not have the money to improve our schools."
But the school district says its pockets aren't nearly as deep as the teachers' union suggests.
"School budgets in California are set in three-year increments, and from July 2018 to June 2021, Los Angeles Unified will spend $24 billion educating students. This includes its entire, existing $1.8 billion reserve," LAUSD said.
The school district said at this rate, it might not even have enough money to meet a required 1% reserve by the 2021-2022 school year.
"When the new school year begins in July 2019, Los Angeles Unified will have about $800 million of the reserve left: $500 million of the $1.8 billion is already earmarked for federal and state-required programs. ... An additional $500 million is being used for a 6% pay raise for all employees, including teachers; to pay for additional nurses, counselors and librarians, and to improve class size," LAUSD said.
"Because of the budget shortfall, the remaining $800 million will be completely depleted by the 2021-2022 school year."
The situation is so bad, the Los Angeles County Office of Education is stepping in. On Wednesday, the agency assigned a team of fiscal experts to work with the school district on a plan to "eliminate deficit spending and restore required financial reserve levels."
The county agency said LAUSD has "failed to adequately address" its deficit spending and is now projecting "higher than expected salary expenses."