Why Doesn't the Willis Tower Topple Over?

Name: Why Doesn't the Willis Tower Topple Over?
Uploaded: 2018-05-15T20:31:37Z
Duration: 1 min 44 s
Description: Chicago is home to one of the tallest buildings in the world: the Willis Tower. So tall that on a windy day, the topmost floors can sway as much as three feet. But what keeps it from falling?

From:Aerial America: Illinois

1m 44s
HD
TV-G

Chicago is home to one of the tallest buildings in the world: the Willis Tower. So tall that on a windy day, the topmost floors can sway as much as three feet. But what keeps it from falling?