David Letterman is no different to the many celebrities and stars who knew Robin Williams, he was extremely upset to hear the news of the legendary comedian's suicide nine days ago, which was obvious when the emotional talk show host opened up about their 38-year friendship.

Robin Williams
Robin Williams committed suicide on Monday Aug 11th

When the tragic news of Williams' death broke, Letterman's 'Late Show' was on a break, but on Monday's show (Aug 18th) he made up for lost time by airing an extended tribute for the late star.

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The 67 year-old host spent ten minutes of the first half of the episode behind his desk fondly recalling his and Williams' early days at West Hollywood's Comedy Store in the 1970's, describing the late 63 year-old's stand-up routine as nothing he "had ever seen before."

"We're like morning dew, he comes in like a hurricane," Letterman added. "And then he finishes and I thought, 'Oh that's it, they're gonna have to put an end to show business because what could happen after this?' ... We didn't approach him because we were afraid of him. Honest to God you thought, 'Holy crap, there goes my chance in show business because of this guy.'"

Letterman went on to say that Williams, who has had a long battle with sobriety and depression, was one of the "kindest, easiest" stars he has ever had to interview on the CBS chat show.

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"Two things would happen: One, I didn't have to do anything - all I had to do was sit here and watch the machine," he continued. "And two, people would watch. If they knew Robin was on this show, the viewership would go up because they wanted to see Robin."

David letterman
Letterman recalled meeting Williams at West Hollywood's Comedy Store in the 70's

The Oscar-winning star was found in his bedroom, fully clothed, and gently suspended in a seat with a belt wrapped around his neck, with one end wedged between the door and the frame of his closet. Williams' widow, Susan Schneider, released a statement and revealed that prior to his death he was dealing with "early stages of Parkinson's Disease, which he was not yet ready to share publicly."

"I am sorry I, like everybody else, had no idea that the man was in pain, that the man was suffering." Letterman concluded.