Construction workers are in the second day of their strike in Chicago and the collar counties today.

More than 2,000 laborers’ are on strike at public and private job sites in 9 counties.

The strike already has shut down construction at the expansion of O’Hare airport and delayed or stopped work at up to 150 state road projects.

The Mid-America Regional Bargaining Association, known as MARBA, represents about 250 contractors.

MARBA wants to bring in a federal mediator to help resolve the contract dispute.

MARBA says the union has not responded to that request.

Union officials say in published reports that they’re independently working out agreements with some of the MARBA contractors.

The union did not return repeated phone calls.