Nancy Kiser, a fifth-grade teacher at Kimball Elementary School, examines a picket sign Tuesday. She'll likely be using it Wednesday. (Ted S. Warren / AP) Seattle teachers voted to go on strike Wednesday, the first day of school, over stalled contract negotiations with the city’s school district. “After bargaining until midnight Monday and for most of the day Tuesday, it was clear that a settlement wasn’t close,” the Seattle Education Association, the union that represents about 5,000 teachers, said in a statement.