The Salem-Keizer Education Association, the union that represents about 2,300 teachers and other educators, declared an impasse Thursday in its contract negotiations with the state’s second-largest school district.

The move is the first step in a process that could lead to a strike, which could begin as soon as April 1.

If a strike occurs, all schools would close, Salem-Keizer Public Schools officials said Thursday night. It would be the first strike in the district’s history.

SKEA president Tyler Scialo-Lakeberg could not immediately be reached for comment.

The district has been bargaining with SKEA, as well as ASK-ESP, which represents about 2,500 district support staff, since last spring. Both negotiations are in mediation.

ASK-ESP has not declared an impasse.

The district and SKEA have reached agreement on many issues, but not on class sizes, compensation and working conditions.

The district’s latest offer to teachers and licensed educators includes a 9.5% raise over two years, increased insurance benefits, a $5,000 retention and recognition bonus, and additional teacher prep time at the elementary level. The total value of the offer is more than $37 million and includes the largest year-over-year increases in memory, district official said.

What’s next?

Thursday was the last session led by a state-appointed mediator.

Now, each side has a week to present its “final” offer.

After a 30-day cooling off period, the district can implement its final offer, or the union may choose to strike (after a 10-day notice).

District officials said they are open to bargaining during that period.

A strike could happen as soon as April 1, when students and staff are scheduled to return from spring break.

Salem-Keizer is Oregon’s second-largest school district, after Portland Public Schools. It has about 38,1857 students across its 65 elementary, middle and high schools.

Teachers in Portland Public Schools went on strike for more than three weeks last November, forcing the district to cancel 11 school days. That won them slightly higher pay, as well as bonuses for those teaching larger classes.

This is a developing story and will be updated.

Tracy Loew covers education at the Statesman Journal. Send comments, questions and tips: tloew@statesmanjournal.com or 503-399-6779. Follow her on Twitter at @Tracy_Loew

This article originally appeared on Salem Statesman Journal: Salem-Keizer teachers declare impasse, step toward possible strike