Dick Clark and Ryan Seacrest Credit: Ron Wolfson/WireImage.com

Rest in peace, Dick Clark.

The legendary TV producer died Wednesday morning of a massive heart attack. He was 82.

The New Year's Rockin' Eve and American Bandstand host was beloved by many, and stars took to their Twitter accounts shortly after news of his passing broke.

Clark served as an idol and mentor to Ryan Seacrest, who took over New Year's Rockin' Eve in 2006 with special appearances from Clark.

Seacrest tweeted Wednesday, "I am deeply saddened by the loss of my dear friend Dick Clark. He has truly been one of the greatest influences in my life. My thoughts and prayers are with his family."

Jenny McCarthy, who cohosted Rockin' Eve with Seacrest, wrote, "RIP dick Clark. You were amazing to work with. U will be missed. Xxxoo" 

Here's what more stars are tweeting:

Joan Rivers: "Very sad to hear about Dick Clark. What a great life. What a great career. Relevant until the end. He will be missed!"

Denise Richards: "My heart goes out to Dick Clark's family and loved ones.... we lost a legend.. #RIPDickClark"

Seth Green: "So saddened by Dick Clark's passing- an innovator, a legend, a man who believed in the greatness of humans. #ThankYou"

Snoop Dogg: "REST IN PEACE to the DICK CLARK!! U were pioneer n a good man!! Thank u sir"

Josh Groban and Olivia Munn simply stated, "RIP Dick Clark." 

Clark's rep told TMZ the TV legend had been in L.A. at St. John's hospital after undergoing an outpatient procedure Tuesday night. Following the procedure, Clark suffered a fatal heart attack. 

He leaves behind three children and a wife, Kari Wigton.