Teachers in Chicago officially went on strike Thursday over class sizes and pay

The city pre-emptively canceled school Thursday for the district’s 360,000 students knowing the strike was imminent. The Chicago Teachers Union wants smaller class sizes and better staffing levels in their new contracts. The city is offering a 16 percent raise over the five-year contract; teachers are seeking a 15 percent raise over three years.

“Most marriages don’t last five years, many marriages, and I don’t like this contract enough to marry it,” union President Jesse Shrakey said.

Mayor Lori Lightfoot said the union continued to bring up additional bargaining issues during negotiations, including a request to shorten instruction time by 30 minutes in the morning. Lightfoot said that will never happen. Teachers also wanted to get paid for unused sick days, which would cost the district $2.5 billion a year.