JERSEY CITY — Strike!

Jersey City's public-school teachers walked off the job for the first time in 20 years today, leading to confusion and some chaos across the 29,000-student district as teachers led boisterous protests outside city schools.

Students all over Jersey City skipped class to join their teachers on the picket line. A loudspeaker outside School 20 blasted Aretha Franklin's "Respect." Teachers at McNair Academic High School yelling "scab" tried to block substitute teachers from entering the school.

The work stoppage comes after months of failed negotiations between the Jersey City Education Association -- the 4,000-member union representing the teachers and other school employees -- and the Jersey City Board of Education. A late-night effort to come to a deal failed at last night's school board meeting.

Teachers here have worked under an expired contract since Sept. 1 and are demanding lower health care costs. They say Chapter 78, New Jersey's 2011 law that revamped how public employees pay for their health benefits, has sharply curtailed their take-home pay.

"I've been in the system for 20 years and I'm finally making a decent salary and now I'm paying $1,400 a month for premiums," a 53-year-old physical education teacher at McNair told The Jersey Journal this morning.

A win for the teachers in this dispute could have statewide implications, as unions across New Jersey could cite Jersey City in their efforts to achieve lower health care costs.

"Quality, affordable health care is a fundamental right for everyone," JCEA President Ron Greco said in statement announcing the strike. "My members are prepared to step up and take on this fight for everyone, knowing full well that it will be a long, difficult process."

The district spent $98.9 million in 2017-18 on health benefits. The employee share of that was $19.9 million. The district's total budget is $682 million.

Teachers are joined on the picket line today by school nurses, paraprofessionals, secretaries, child study teams, guidance counselors and non-certified administrators. Security guards are not striking.

The nine-member school board has met three times this week in an effort to come to a deal, most recently on Thursday, when it convened until 12:30 a.m. Friday. It voted 4-2 to approve a contract offer — three board members cannot vote because they were endorsed by the teachers union in November's elections — but by that time teachers had already been told the strike was on.

"We are no doubt disappointed with the JCEA leadership's reckless and irresponsible decision to strike work," Board of Education President Sudhan Thomas said in an email. "The JCEA leadership's actions will cause immense hardship to the 30,000 students we serve, the parents, the citizens of Jersey City and create additional pressure on the district while we are combating a $ 70 million short fall for our budget 2018-2019."

Negotiations resumed today at 9 a.m.

"We greatly hope that we can resolve issues around the contract quickly," school district spokeswoman Maryann Dickar said.

In a robocalls to parents sent last night and this morning, the district laid out the half-day schedule and said the Morning Stars, Casper and afterschool programs have all been canceled, but that breakfast and lunch will be served. The district is also maintaining a strike update page on its website.

"The school board has been working hard to negotiate an agreement with the teachers' union and we are disappointed that the union has decided to take this disruptive step," the message said.

The school board approved a plan last night to seek an injunction compelling teachers to return to work. It's not clear if a hearing has been scheduled yet.

Rebecca Kolins Givan is an associate professor in the Rutgers School of Management and Labor Relations who studies labor relations in public education. She said today's action is part of a "strike wave" that started with West Virginia's statewide teacher strike, which ended March 6 after nine days.

Teachers in Oklahoma, Arizona and Kentucky may also walk off the job.

"Teachers have realized that business as usual is not getting them what they need," Givan told The Jersey Journal.

The Jersey Journal's Caitlin Mota contributed to this report.