1

The 21st Aon building Step Up

The 21st Aon Center Step Up for Kids brought 2,500 climbers up the 80 stories of Chicago’s third tallest skyscraper. (Yunyi(Jessie) Liu/MEDILL)

The 21st Aon building Step Up for kids brought 2,500 climbers up the 80 stories of Chicago’s third tallest skyscraper. (Yunyi(Jessie) Liu/MEDILL)