Neither will anyone else - they're changing the name to the Willis Tower.
The Willis Tower was the tallest building in the world from 1974 to 1996.
On July 16, 2009, the building was officially renamed the Willis Tower.
They use Willis Tower for cover before using wing suits to descend into the city streets.
The top of the Willis Tower is the highest point in Illinois.
The Willis Tower was the first building for which this design was used.
Many broadcast station transmitters are located at the top of the Willis Tower.
Higher levels may be smaller in area than the ones beneath (a prominent feature of the Willis Tower).
The company occupies 16 floors of the Willis Tower.
All of the other area stations broadcast from the top of the Willis Tower.