CHICAGO (AP) — Workers at Chicago’s O’Hare International Airport are expected to walk off the job over union rights and an hourly wage of $15.

About 500 workers have committed to the strike on Tuesday. They include cabin cleaners, janitors, wheelchair attendants and baggage handlers.

The workers are employed by private contractors. Strike organizers say many work for minimum wage. They’re trying to unionize with the help of Service Employees International Union Local 1.

Organizers say they expect delays and disruption, particularly for United and American airlines. But Chicago Department of Aviation officials say they don’t anticipate disruptions.

The strike is part of a nationwide campaign for higher hourly wages, including for workers at other airports and fast-food restaurants. Thousands plan to walk off the job at McDonald’s restaurants.

Chicago @fightfor15 protestors block Chicago Ave W of Damen #NBCSky5 live @nbcchicago @KyeMartinNBC @LaurenPettyNBC pic.twitter.com/qLmlyxL6y1

— Mike Lorber (@NBCSky5) November 29, 2016

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