Indiana State Fair stage collapse
At 8:46 p.m, on August 13, 2011, a wind gust from an approaching severe thunderstorm hit the roof structure of a temporary outdoor concert stage at the Indiana State Fair in Indianapolis, Indiana, U.S., and caused its collapse. The structure landed among a crowd of spectators, killing seven people and injuring fifty-eight others.
Source: Wikipedia — Indiana State Fair stage collapse (CC BY-SA 4.0)