Employees, represented by the Service Employees International Union, have decided to postpone a strike they had scheduled to take place in 10 major U.S. airports on Tuesday. It was estimated that as many as 2,000 employees were planning to participate in the strike. The employees decided to postpone their strike in the wake of the Brussels attack. The majority of these workers are baggage handlers, security workers and airport cleaners. These workers are striking over retaliation against unionization and wages.
See "Airports Workers Cancel Strike Planned for U.S. Hubs Following Brussels Attacks", Luz Lazo, The Washington Post, March 23, 2016