An employee demonstrates a Blackberry Playbook tablet at a Best Buy store on April 19, 2011 in Chicago, Illinois. The tablets, made by Research In Motion, went on sale today in the United States and Canada. (Photo by Scott Olson/Getty Images)

A woman wears roller skates with lights on the bottom at Rich City Skate in Richton Park, Illinois, January 12, 2015. A handful of decades-old skating venues put Chicago at the center of a vibrant African-American subculture of urban roller skate dancing that stretches from Atlanta to Detroit and from Los Angeles to New York. While mainstream roller skating has been on a long decline, a new generation of skaters travel a circuit of rinks around the country to compete and show off their moves. (Photo by Jim Young/Reuters)

Democratic presidential candidate and US Vice President Kamala Harris reacts as she holds a photographer's camera while flying on Marine Two, on her way to O'Hare International Airport, Chicago, Illinois, on August 20, 2024. Harris is traveling to Milwaukee, Wisconsin, to speak at a campaign event. (Photo by Kevin Lamarque/Pool via AFP Photo)

Chamrock, an Irish wolfhound, sports a green coat as he waits for the start of the St. Patrick's Day parade on March 17, 2012 in Chicago, Illinois. Tens of thousands took advantage of record high temperatures and sunny weather to attend the city's annual St. Patrick's Day celebration. (Photo by Brian Kersey/Getty Images)

A five-week-old orphaned Southern Sea Otter pup rests on a rubber mat after arriving at the Shedd Aquarium's Abbott Oceanarium in Chicago, Illinois October 28, 2014 in this handout photo provided to Reuters on November 5, 2014. The stranded pup was found on September 30 on Coastways Beach in California and was rescued the next day to be brought back to health at the Monterey Bay Aquarium. Southern sea otters were listed as “threatened” under the U.S. Endangered Species Act in 1977. (Photo by Brenna Hernandez/Reuters/Shedd Aquarium)

Workers at the World's Finest Chocolate company weigh what they hope will be a world record chocolate bar September 13, 2011 in Chicago, Illinois. The candy bar, weighing 12,190 pounds, standing nearly 3 feet high and measuring 21 feet long beat the previous record chocolate bar by more than a ton. (Photo by Scott Olson/Getty Images)

A Research In Motion BlackBerry device is shown on October 12, 2011 in Chicago, Illinois. A three-day disruption of service that has previously affected users in Europe, the Middle East, Africa and India has now spread to customers in North America. Customers are experiencing patchy email service and receiving no access to browsing or messaging. (Photo Illustration by Scott Olson/Getty Images)

Mike Branch helps customers shop for a Halloween masks at Fantasy Costumes on October 28, 2011 in Chicago, Illinois. The store, which had long lines at the registers at 4 AM this morning, is open around the clock through Halloween to help keep up with customer demand. Retailers nationwide are expecting record sales for Halloween merchandise this year with shoppers spending close to $7 billion dollars to celebrate the holiday. (Photo by Scott Olson/Getty Images)