(NewsNation) — School has been called off for more than 50,000 students for a third day in Seattle as teachers continue to strike.

Classes were set to start Wednesday, but thousands of Seattle educators have been picketing near the city’s public schools over issues including pay, mental health services and more support for multilingual and special education students.

According to the Seattle Times, the strike was called at midnight Wednesday after months were spent trying to negotiate a deal with the Seattle Education Association that represents around 6,000 teachers.

“I started teaching right at the start of COVID, as we went into online school, a big tumultuous time when students needed more resources and help to do well,” said Kara Alden, an eighth-grade English teacher picketing outside Jane Addams Middle School in north Seattle. “We’re back in person and they still need those supports, in social-emotional health, for our multilingual learners to get the education they deserve. The district is not providing those supports.”

On Thursday, the district said they are “making every effort to return students to classrooms.”

It’s the first time since 2015 the district has gone on strike.

The Associated Press contributed to this report.