Chicago celebrates 50 years of Skydeck at Willis Tower CHICAGO (CBS) -- Skydeck Chicago, the observation deck atop Willis Tower, the tallest building in Chicago, is celebrating its 50th anniversary.

Four men had a terrifying few moments when the glass floor they were standing on 103 stories above Chicago in the Willis Tower observation deck appeared to develop cracks.

He also designed this interactive Chicago-themed museum that visitors move through on their way to the 103rd-floor observation deck. On a clear day, the views stretch for 50 miles across four states.

After an extensive renovation, an immersive new exhibition and reimagined observation deck open at Chicago’s Willis Tower, inviting visitors to explore the city’s past, present, and future.

About Willis Tower Located in the heart of downtown Chicago, Willis Tower is an iconic urban destination and state-of-the art, human-centered workplace.

Life-long Chicagoans grew up, staring up at the Sears Tower. But very few have actually visited the building that for a long time held the title of world’s tallest. Times have changed. It&#82… ...

Here's some background information about Willis Tower, formerly the Sears Tower, located in Chicago.

(CNN) — Here’s some background information about Willis Tower, formerly the Sears Tower, located in Chicago.

The annual "Skyrise Chicago" stair climb features climbers ascending 2,109 steps to the Willis Tower Skydeck to benefit the Shirley Ryan Ability Lab.