CHICAGO (CBS) — Teachers at Geneva School District 304 went on strike overnight, after contract negotiations broke down over a lack of progress on salary issues. The strike impacts more than 5,800 students at nine schools in west suburban Geneva.

It’s believed to be the first teachers’ strike in the district.

Classes, after school programs, and athletic activities have been cancelled for students at all nine schools in the district, with the exception of a few programs. The district said students won’t be back in school until the strike is called off.

The Geneva Education Association negotiated with the school board for nearly eight hours Monday night before talks hit a wall, and the union went on strike.

“We thought we were making progress last night, and ultimately the board didn’t see it that way,” said Jason Santo, an English and journalism teacher at Geneva High School.

Union president Kevin Gannon said the big issue is compensation for teachers.

“Our ask isn’t to be the highest-paid teachers in the county, even though our schools are rated highest in the county. We’re asking to be paid the average, the county average, throughout our career,” Gannon said.

Teachers have been seeking a traditional step and lane salary schedule, meaning teachers would get paid more for their experience and education, but the board wants to move away from that model.

The union said the board is proposing to give newer teachers higher percentage raises, while giving a smaller raise to teachers with experience. The union said, with the board’s offer, the starting salary would increase by 17 percent over four years of the contract, while tenured teachers would see only a 1.2 percent raise during the same four years.

Teachers also have raised concerns about health insurance, stipends, and summer pay.

Union officials said they know this is a stressful time for families in the district.

“This is a short-term sacrifice, so that in a long-term we can hire and retain the highest-quality teachers for their children in the long-term,” Gannon said.

The Geneva Education Association represents approximately 450 teachers in the district. They said going on strike was a last resort.

“We want to be in that building. We want to be inside with the students today, instead of out here, because we value education; but, ultimately, for ourselves, for our family, and really for the community, we had to take this final step to go on strike,” Santo said.

Santo said students support their teachers.

“They understand how important the teachers are to them. They know that we don’t want to be doing this, that we want to be in the classroom. They know how much we value being around them, and working with them, but they know that this has to be done. They know the teachers deserve to be treated fairly, and get a fair contract,” he said.

The union and the school board have been negotiating since February, and teachers have been working without a contract since August. No new talks have been scheduled as of Tuesday morning, but the union said it hopes to meet with the school board sometime Tuesday to resume talks.