The family of celebrity zookeeper and TV show host Jack Hanna said he's been diagnosed with dementia and will retire from public life.

David Letterman's marquee has been up on the Ed Sullivan Theater for decades, but it's now being torn down. CBSN's Meg Oliver and Vladimir Duthiers have more.

After 22 years making audiences laugh in the studio and across the nation, "Late Show" host David Letterman has delivered his final punch line. CBS News' Suzanne Marquez ...