The news was hard to believe.Bob Saget diedat the age of 65 on Sunday, as first reported byTMZ.

At time of writing, a cause of death was unknown (viaPeople).

Fans were immediately reeling onTwitter, with celebrities reacting with disbelief over the comedian’s passing.

John Stamos and Bob Saget smiling together

Fellow comic Marc Maron tweeted, “Oh no.

Truly one of the nicest guys and so funny.

Jason Alexander tweeted, “I know that people lose loved ones, good people, every day.

John Stamos and Bob Saget in a recent photo

No one gets a pass.

But the loss of Bob Saget hits deep.

If you didn’t know him, he was kind and dear and cared about people deeply.

He was the definition of ‘a good egg.’

Too soon he leaves.

Of course, the star’s"Full House” co-starsare likely deeply impacted by his tragic loss.

“To say we are like brothers is an understatement,” Saget wrote.

“We have been through so much together for 35 years.

High, lows- The usual you go through with your closest of people in your life.

He has always been there for me.

Even when I could be unbearable' (viaToday).