Actor and comedian Garry Shandling died of a massive heart attack at a Los Angeles area hospital Thursday, TMZ reported. He was 66 years old. Shandling was reportedly healthy and did not suffer with any known illness before his death.

There was a 911 call placed at the star’s home Thursday. He was reportedly alive when medics arrived.

One of Shandling’s main claims to fame is “The Larry Sanders Show,” which aired on HBO from 1992 to 1998. He also appeared in films such as “Captain America: The Winter Soldier,” “Iron Man 2.” and “Zoolander.” In addition, he served as host of the Emmy and Grammy awards shows numerous times.

The comedian began his career in the 1970s after he was injured in a car wreck. “The accident gave me some actual insight into life and its impermanence, and there is something more to it than what meets the eye,” Shandling told the Archive of American Television last year. “And I realized I best try to figure out who I authentically was and I could do that through standup.”

Fellow comedians and other celebrities are mourning via social media, with some of their tweets appearing below:

This is a developing story.

Follow me on Twitter @mariamzzarella