Bill Cosby refuses to address sexual assault allegations on NPR interview, will no longer appear on David Letterman's show

Bill Cosby, in the midst of a serious PR crisis as accusations about him sexually assaulting women make headlines around the world, has decided to stay silent. In an interview on NPR's "Weekend Edition" that aired Saturday (where Cosby and his wife appeared to talk about loaning works to the National Museum of African Art), Cosby, 77, didn't say a word when host Scott Simon asked him about the allegations. In the past, Cosby has repeatedly denied these claims.