"He has expressed an interest in what Chicago's doing. And I think that it would be a tremendous investment and job creator, an economic engine for the city that will pay dividends for decades ahead," Emanuel added. "They have shown interest, and now I've asked them to come to the city of Chicago, after I sent my team out to California, Southern California to explore it and explore their interest. They are very interested, and we're going to have them now out to the city to explore further what we are doing and planning, and too see if the tunnel approach is an alternative to the ones we've been discussing."