Chicago Cubs: When the stadium is old and exposed to years of Chicago winters, there are bound to be some structural issues. That was realized one rainy 2004 afternoon at Wrigley.
On June 18th, 2004, the Cubs hosted the Oakland Athletics in an interleague matchup at Wrigley. Matt Clement pitched a great game, but the Cubs lost 2-1. That was not the story at the end of the day. What got more attention was the fact that during the game, the stadium began to crumble literally.
Chunks of concrete fell from the upper terrace and just missed hitting a couple of fans. While the stadium was assured to be structurally sound by inspectors, that did not stop a piece of the then-90-year-old stadium from falling apart. This was a part of several incidents this season where chunks of concrete fell. It is particularly scary when it almost hits people.
These incidents resulted in further extensive inspections of the ballpark and putting up some janky-looking netting all around the ballpark. Not sure how safe fans felt sitting in a 90-year old ballpark with their protection lies in the hands of nets. Luckily nobody was injured during these incidents.
Is seeing an old building crumbling unusual? No. But it is safe to say fans do not expect to see the ballpark crumble as they attend a ballgame.