Legendary comedian and actor Garry Shandling died mysteriously Thursday morning after falling ill the day before. While his official cause of death remains unknown, a glimpse into his final moments reveals much about what may have happened to “The Larry Sanders Show” creator.

According to TMZ, Shandling, 66 at the time of his death, wasn’t known to be sick. He was, however, complaining that he wasn’t feeling like himself on Wednesday. The comedian reportedly was in contact with a friend of his who is a doctor. Sources tell TMZ he was complaining about feeling achey and short of breath. His concerns were serious enough that the physician paid a visit to Shandling at home and warned him that if his condition persisted he should visit an emergency room.

Shandling placed a call to 911 around 10: 30 a.m. PDT on Thursday. TMZ reports that he lost consciousness during the call. Paramedics are said to have arrived at the comic’s home, broken down the door and found him. His pulse was reportedly weak, though he was still alive. Shandling was pronounced dead shortly after at a Santa Monica, California, hospital.

Several actors, actresses and comedians have taken to Twitter to express their condolences. Amy Schumer wrote that she would carry his “kindness” and “generosity” with her forever, thanking him for the many laughs throughout the years. Actor Carl Reiner tweeted that the world “can't afford to lose” great minds like Shandling’s.

No further information about Shandling’s death has been released at this time. He was not married and left behind no children. It is not yet known when or where his funeral will take place.