David Letterman's announcement that he will be retiring came as a shock to everyone.
Letterman announced to his "Late Show With David Letterman" audience on Thursday that he will be retiring sometime in 2015.
The iconic host told his fans, "I just want to reiterate my thanks for the support from the network, all of the people who have worked here, all of the people in the theater, all of the people on the staff, everybody at home, thank you very much."
The comedian joked, "What this means now is that Paul and I can be married."
Fox News reports that David Letterman may have thought about retiring because of the ratings of younger hosts including Jimmy Fallon and Jimmy Kimmel.
An insider told FOX411, "David is older now; he had heart surgery some time ago and sees both Jimmy Kimmel as well as the more formidable Jimmy Fallon now gaining on him."
The source continued, "Fallon is getting record ratings so Letterman will segue out while he's on top. It's dignified. If Fallon weren't so hot, he might have stuck around longer."
Letterman has reportedly been averaging 2.85 million viewers, while Fallon is getting around 4.3 million and Kimmel 2.7 million.
The Wrap.com reports that a possible candidate to fill David Letterman's spot will be Conan O'Brien, who will end his contract for "Conan" in 2015.
Other candidates include "Late-Late Show" host Craig Ferguson and Chelsea Handler.
After the announcement that David Letterman is retiring, stars took to Twitter to show how much he will be missed.
President Obama wrote, "There are more than 10 reasons #DavidLetterman will be missed."
"Girls" star Lena Dunham tweeted, "I love Letterman but I am really excited about what this could mean for the diversification of late night. Trying not to be a pessimist."
Ellen DeGeneres wrote, "David @Letterman announced he's retiring in 2015. It's been 31 incredible years. Television won't be the same without you, Dave."
Fellow comedian Ricky Gervais commented, "Cheers to @Letterman. A king, a king-maker, and probably the man most to blame for inflicting me on America. See you soon."
