Chicago's bid team says a $500 million insurance policy would kick in before residents have to pay a dime.
On Wednesday in Lausanne, Switzerland, leaders of the four cities competing to host the 2016 Games made their most important pitch to date.
Chicago 2016 brought in several stars of the Olympic movement to offer IOC members a guided tour of a city many of them have never seen.
"Hi, I'm Shawn Johnson, 2008 Olympic gold medalist in gymnastics we're just a few steps from Northerly Island, which will become Northerly Island in 2016. Take a look at this great spot. The lake, skyline. It's gorgeous," said Johnson.
The race now appears to have two front runners.
Chicago has the plan, Rio has the passion. That's the consensus among many Olympics watchers, who now think this race is down to those two cities, but the competition is far from over.
IOC members sorted through pictures and plans as Mayor Richard Daley and his team made their pitch.
For an hour and 45 minutes Chicago made its case and fielded more than a few questions about its plan to privately finance the Games.
"To make a different arrangement where you have both public and private sector and not-for-profit working together, that is a much better system. That's where the rest of the world will go with financial arrangements," said Mayor Daley.
"I think that'll be the future, I really believe, because you can't put all the burden on government," said Patrick Ryan, Chicago 2016 chairman.
Rio, Madrid and Tokyo told IOC members their government guarantees ensure the money will be there, even in a global recession. But several IOC members tell ABC 7, they're not worried about Chicago's ability to raise the $4.8 billion necessary to host the Games.
"I think there are sufficient guarantees to make any possible risk zero; so I myself am satisfied with their answer," said Francisco Elizalde, IOC member, Philippines.
"They were good questions, solid questions and I think they answered them well," said Jim Easton, IOC member, United States.
Chicago is relatively unknown to many IOC members. So American Olympians offered the IOC a virtual guided tour meant to underscore that the Games would be played in the heart of the city.
"I have ideas but I will not express them," said Franco Carraro, IOC member, Italy.
"A lot of people want to pinpoint us vs. Rio de Janeiro, but we're in competition with all the cities. No one, it is not decided by just two cities at all," said Mayor Daley.
Rio projects it'll have to spend three times as much money as Chicago to get its airport and mass transit system prepared for the Games. But that's part of their pitch. They are telling the IOC if they want the Olympics to truly leave a positive legacy for a city, country and continent Rio is the place to go.
ABC 7's Ben Bradley is traveling with the mayor. Check out Ben's blog.