A Toon killed his brother... Dropped a piano on his head.
8 seconds sound clip from the Who Framed Roger Rabbit movie soundboard.
You can hear this line at 00:13:57 in the Blu-ray version of the movie.
Quote context
[...]
- Hey, wait a minute. Wait a minute. I know.
- You're working for Little Bo Peep. She's lost her sheep and you're gonna help her find them. Hey?
- Get this straight, meatball. I don't work for Toons!
- A Toon killed his brother... Dropped a piano on his head.
[...]