Warsaw radio mast

On 10 August, 1991, this structure in Konstantynow, Poland collapsed during renovation work. Three people were killed and 12 injured when it came down. Until its collapse, it was the tallest structure in the world. Before its collapse, it was 647 meters (2,120 feet) tall.It was designed by an architect named Jan Polak

With its collapse, the KTHI-TV television tower outside of Fargo, North Dakota, USA, became the world's tallest structure, standing at 629 meters (2,063 feet) tall.