Thousands of San Francisco teachers went on strike on Monday, citing an impasse with the school district over wages and health care benefits.

The action marks the first teachers’ walkout in the San Francisco Unified School District in almost 50 years.

Teachers stressed that the strike, which has shuttered schools for roughly 48,000 students, was launched after long-stalled negotiations over issues such as raises and insurance coverage. At the same time, the cost of living in the region remains one of the highest in the country.

“It has taken over 10 months of sounding this alarm, negotiating, asking nicely and hearing unfulfilled promises to get to this point,” Cassondra Curiel, president of the United Educators of San Francisco union (UESF), said at a press conference on Monday. “The proposals the district came with to address special education, health care and salary just didn’t go far enough.”

The union represents roughly 6,000 school staff, including teachers, social workers, nurses and librarians. It’s pressing for 4.5% annual raises for two years, and for dependents’ health care benefits to be fully covered.

The district has countered with 3% annual raises for two years and 75% coverage for dependents or a $24,000 health benefit allowance.

On Monday, teachers said that they were making these demands because of the financial pressures they face to live and work in the Bay Area. As The 19th reported, the salary for a new credentialed teacher is about $80,000 in San Francisco. The annual salary that a single adult needs to live “comfortably” in the city is roughly $122,000, according to a CNBC report.

Per a report by the district, the city’s high cost of housing is a factor in the 10% attrition rate it sees among teachers each year.

“Our students lose out when their teachers can’t afford to stay,” UESF wrote in a social media post.

Teachers also sounded the alarm about a dearth of resources for special education programs and the ramifications for students.

The district has countered by suggesting that it faces financial constraints that prevent it from meeting certain demands.

“Unified School District does not have unlimited funds,” superintendent Maria Su said during a Monday press briefing. “We are managing a structural deficit, and we are currently still under state oversight.”

UESF argued that the district had millions of dollars in its reserves, while school officials claimed that those funds face their own restrictions.

UESF also heralded agreements that had already been reached over sanctuary school policies and restrictions on artificial intelligence and staffing.

In recent months, workers in an array of industries have been calling for better conditions and fair pay as they’ve grappled with understaffing and challenging workloads. Other major labor actions have taken place as well, including a walkout by thousands of Kaiser Permanente workers in California and Hawaii, and a strike by thousands of nurses in New York City.

District officials said Monday that school would be out of session again on Tuesday as the two parties continued their negotiations. The district has provided families with independent study packets and set up locations where staff are distributing free meals to students throughout the city.

“You can expect to see strong picket lines until that agreement is achieved,” Curiel said during a Monday press conference.