UPDATE: The Brookline teachers union and School Committee reached a tentative contract agreement early Tuesday, May 17.

In a rare gesture of defiance and frustration, teachers went on strike Monday morning in Brookline, marking only the second time educators in Massachusetts have picketed in more than a decade.

Hundreds of educators in red shirts banging drums and cowbells appeared in front of the high school, along Route 9 and at local elementary schools, saying they want the School Committee to agree to cost-of-living pay increases as well as more class preparation time. Lead negotiator Eric Schiff, a high school guidance counselor, said teachers have been demoralized by the School Committee's unwillingness to accept their proposals, including one that could help hire and retain diverse teachers.

"We're in these buildings every day," Schiff said, pointing to a new high school building and Brookline's overall wealth. "We come to the table with proposals to not only improve teaching, but improve learning."

The last time any of the state's unionized teachers walked off their jobs was in Dedham in 2019, for one day. In Massachusetts, it's illegal for public sector employees to go on strike.

Over the weekend, Brookline teachers were offered a six-year contract retroactive to 2020. That includes a 6% pay hike for the first three years and an 8% increase for the second three years. Those increases are in addition to a nearly 4% raise already offered to experienced teachers.

Weekend negotiations ended without resolution at 4 a.m. on Sunday. Later the same day, Superintendent Linus Guillory sent an email to parents announcing the district was canceling school Monday.

"The district has made the difficult decsion to close all schools," he wrote. "There will simply not be the staffing capacity to operate all schools safely, nor can [the district] provide the structured education required by the state for the day to legally count as a school day."

Guillory added that officials were "determined to come to an agreement" and that mediation could continue until late Monday.

Teacher Zach Broken Rope was one of the first to arrive for the strike at Brookline High School. He carried a sign that said he's had to work part-time jobs as a bouncer, Lyft driver and DoorDash deliveryman to supplement his teaching income and pay his bills.

Noting his Native American ancestry, Broken Rope also said he's most bothered by the School Committee's lack of action to establish contractual policies that would help keep new and diverse hires on board.

"They gave [us] a pink slip three years ago, along with 70 other percent of the other teachers of color in the district," he said. "We're asking them to commit to equity and justice, which is what they claim to care about as a district. And so we're asking to make a commitment in writing."

The Massachusetts Teachers Association, the state's largest teachers' union, issued a statement saying it supported Brookline educators, who are approaching their third year of working without a contract.

"A fatiguing pattern of never-ending bargaining has set in, indicative of an environment where educators' concerns and needs — which reflect those of the students and the community — are being ignored," the union said.