When Mrs. O'Leary's cow kicked the lantern in Chicago town, they say that started the fire that burned Chicago down.
18 seconds sound clip from the Gilda (1946) movie soundboard.
You can hear this line at 00:50:56.995 in the Blu-ray version of the movie.
Quote context
[...]
- Sure, I heard what you said. You're going to take me there and pick me up.
- Who do you think you're kidding, Johnny?
- That's the story that went around, but here's the real lowdown.
- Put the blame on Mame, boys. Put the blame on Mame.
- That's the story that went around, but here's the real lowdown. (2)
[...]