Teachers in the nation’s second-largest school system went on strike Monday, drawing a line over not just pay but also issues that resonate in Philadelphia, including class sizes, staffing, and the role of charter schools.

Thirty thousand educators walked off the job in the first Los Angeles Unified School District strike in 30 years. They had been working without a contract for more than a year.

School buildings will be open for the nearly 500,000 students in traditional public schools, and district officials have said that there will be some form of instruction, but there will be far fewer adults than usual to provide it, and no teachers, counselors, librarians, and nurses, all of whom are members of United Teachers Los Angeles (UTLA).

Philadelphia Federation of Teachers president Jerry Jordan is watching the proceedings closely, and had urged all Philadelphia teachers to wear red Monday in solidarity with the striking L.A. educators. His union, which worked without a contract for nearly five years before reaching a deal in 2017, has a pact that lasts through August 2020, and will likely be back at the negotiating table this year.

“I said to my members, ‘What’s happening to Los Angeles teachers is what will happen here; don’t think that it won’t,'” Jordan said.

While Jordan said he is optimistic that the PFT, which has 11,000 members, can avoid a strike, it now legally has the option of calling one.

Under the state takeover that lasted from 2001 until last June, the Philadelphia teachers' union was legally forbidden from striking. (The PFT called a brief weekend strike in 2000, but classes were never interrupted; its last substantial strike, a 50-day walkout, occurred in 1981.)

In many ways, the L.A. strike is about more than one particular contract. It is, many education watchers say, about the under-funding of public education generally and the way traditional public schools have been tested and strained in recent years.

The district, led by Austin Beutner, a former investment banker, says it doesn’t have the money for much of what UTLA proposes. New California Gov. Gavin Newsom last week proposed more funding for public schools, but the union says it’s a Band-aid, not a long-term fix that would provide students access to the services and staff they need.

Jessica Way, a teacher at Franklin Learning Center, wrote in a Facebook post that the strike “is about the slow collapse of the American public education system.”

“It is about 45 students in the classroom, lack of support staff, and school buildings in horrible condition,” Way wrote. “It is about kids dying from asthma due to a lack of nurses. It is about pushing back against a system of privatization in our cities that has created a school system MORE separated by race and class. It is about the irresponsible under-funding of public schools in cities and rural areas all across the country. It is about Detroit, Chicago, and Philadelphia.”

Way, a member of the activist Caucus of Working Educators within the PFT, chipped in to buy teachers at Bancroft Middle School in Los Angeles food on the picket line. The caucus is urging others to do so, too.

The district stressed that it is open for business despite the strike, urging parents to send their children to school, but it’s unclear how many children will show up.

Los Angeles teachers' salaries range from about $50,000 to $90,000. Teachers want a 6.5 percent pay increase.