Casey Kasem, the famous radio personality who hosted shows like "American Top 40" and "Casey's Top 40," passed away this morning at 82. The disc jockey, actor, and activist, whose voice was a familiar fixture from coast to coast, had been in poor health for several months.

His daughter Kerri announced Kasem's passing on Twitter:

For decades, Kasem was also famously the voice of Shaggy from the childhood cartoon staple Scooby-Doo. Here's Kasem breaking out the Shaggy voice during a telethon to raise money for muscular dystrophy. 

And lastly, here is a clip of Kasem's final sign-off from "America's Top 40" back in 2004 before he handed the reins to Ryan Seacrest.

Included is his signature line: "Keep your feet on the ground and keep reaching for the stars."