BELLEVUE, Wash. -- Teachers here hit the picket lines Tuesday on what was supposed to be the first day of school, as negotiations with the Bellevue School District remained deadlocked.

Despite a mediator's presence during negotiations that ran through the long holiday weekend, the union and district were unable to come to terms on compensation and teachers' freedom to stray from the established curriculum. Both sides are scheduled to resume talks with a mediator early Tuesday afternoon.

In the meantime, about 1,200 teachers spent all night making picket signs, and the district's 16,000 students will have an extended summer -- but it's not clear for how long.

"I'm really sad that we're here; sad that we have to be here," said teacher Byona Golding says.

The teachers are demanding more control over their lesson plans, better health care benefits and an 11-percent increase in pay over the next three years.

"Cost of gas is going up, cost of living is going up. So we want to stay competitive and make sure we attract the best," said teacher Randy Litzenberger. "Bellevue kids deserve the best teachers. We want to make sure that happens for the long run."

The district says there's room to be more generous with benefits and allow teachers more control over how they teach, but there is no room in the budget for the pay raise, which would cost the district $3.8 million.

"To offer them what they're asking for would really call for significant cuts in positions, in programs and for class size increases," said school district spokeswoman Anne Oxreider. "I just know there's a sense that we want to keep working on this. We want to get somewhere, but I don't think anybody's predicting the outcome."

In June, the Bellevue Education Association voted strike lines if they did not have a contract by September 2.

"It makes no sense to start school and have poor education where education is lacking in some way," said Michele Miller with Bellevue Education Association. "And so we're asking for some patience until we can guarantee the education they get in the classroom is quality education."

Parents and students who support their teachers' decision are hoping for a quick resolution.

"We really hope there is a compromise and it's reached quickly because there will be consequences for students, teachers and the administration," said student Stephen Bronski.

And for parents who have day care issues.

"(This strike) is very hard to us," said parent Yanan Zhang. "We both have to work and we have no plan for this little one."

Bellevue city leaders said they'll support an expanded Boys and Girls Club day camp on Tuesday to provide child care and could open two additional day camps if the strike continues through Thursday. Extracurricular activities such as after-school sports will go on as scheduled.

The BEA last went on strike 28 years ago.