By the CNN Wire Staff
(CNN) - Tens of thousands of teachers and support staff in Chicago are set to go on strike Monday after their union and school officials failed to reach a contract agreement, the union president said.
"Negotiations have been intense but productive, but we have failed to reach an agreement that would prevent a labor strike," Chicago Teachers Union President Karen Lewis told reporters late Sunday night.
Minutes earlier, the president of Chicago's school board said officials offered the city's teachers a contract including pay increases and other measures they'd requested.
"We've been as responsive as we know how," David Vitale told reporters just before 10 p.m. CT (11 p.m. ET) Sunday.FULL STORY