David Letterman is back from vacation and used part of Monday's Late Show to pay tribute to Robin Williams.
Williams took his own life last week in his California home. The actor and comedian's wife says the 63-year-old was in the early stages of Parkinson's Disease, along with battling depression and anxiety at the time of his death.
Letterman says he met Williams 38 years ago at the Comedy Store as they both started their careers. Letterman says it wasn't until Williams started making appearances on the Late Show to promote his various films that the two really started to get to know each other. A 10-minute tribute to Williams on Monday's show included a montage of his 50 appearances on the Late Show.
Watch the tribute in the video player below.