Seattle teachers and support staff marched in picket lines on Wednesday during what was supposed to be the first day of school, waging their first such strike in three decades after contract talks between the district and union failed.

The 5,000-member Seattle Education Association voted unanimously on Sept. 3 to strike on the first day of school for some 53,000 students in almost 100 public schools if an agreement could not be reached for a tentative contract, said union spokesman Rich Wood.

The two sides remained at loggerheads over several key issues after extended talks collapsed late Tuesday, including teacher pay increases, teacher evaluations and the length of the school day.