The collapse of the Tay Bridge. In 1879, a railroad bridge spanning the Firth of Tay near Dundee, Scotland gave way during a violent storm as a train was passing over. All souls aboard were lost, between 60 and 80 people. The event lead to a serious reconsideration of engineering standards.
Perhaps even worse, it lead to the writing of The Tay Bridge Disaster, the magnum opus of Scottish poet William McGonagall, generally considered the worst poet in history.
First and last verses:
"Beautiful railway bridge of the silv'ry Tay
Alas! I am very sorry to say
That ninety lives have been taken away
On the last sabbath day of 1879
Which will be remember'd for a very long time."
....
"Oh! Ill-fated bridge of the silv'ry Tay,
I now must conclude my lay
By telling the world fearlessly without the least dismay,
That your central girders would not have given way,
At least many sensible men do say,
Had they been supported on each side with buttresses
At least many sensible men confesses,
For the stronger we our houses do build,
The less chance we have of being killed."
Oh, dear.