Guests including Academy Award-winning actress Kate Winslet escaped uninjured when fire destroyed Richard Branson’s Caribbean home in the middle of the night, the British businessman said Monday. The Virgin Group boss said about 20 people, including Winslet and her children, were staying in the eight-bedroom Great House on Necker, his private isle in the British Virgin Islands. Branson said he was staying in another property around 100 yards away with his wife, Joan, and son Sam, 25. He said the fire broke out around 4 a.m. during a wind and lightning storm, and Sam managed to help evacuate Winslet and other guests from the house. Branson said the guests, including his 90-year-old mother and his daughter Holly, 29, all managed to get out safely. Winslet’s spokeswoman, Sara Keene, confirmed the actress was unharmed. Branson said the house was “completely destroyed” and the fire was not entirely out Monday. … David Letterman was back at “Late Show” on Monday after a two-week vacation, his first day at work since a threat against his life was posted on a jihadist website. Outside the Ed Sullivan Theater before the midafternoon taping, it was pretty much business as usual. CBS has declined to comment on any special security measures being taken for the busy day (which, as usual, calls for a taping of Thursday’s show after Monday night’s show is wrapped). A bomb-sniffing dog was led around the periphery of the midtown Manhattan theater. Last week a frequent contributor to a jihadist website posted the threat to Letterman. He urged Muslim followers to “cut the tongue” of the late-night host because of a joke and gesture the comic had made about al-Qaida leaders on his CBS show.