According to the Associated Press, the Oscar winner was with her boyfriend and family at Necker Island's eight-bedroom Great House when a 4 a.m. fire broke out during a wind and lightning storm. Branson was staying in a nearby property with his wife and son, who helped Winslet and approximately 20 guests -- which included his daughter and 90-year-old grandmother -- evacuate safely.
Writing on his personal blog
, Branson posted photos and video of the house fire and thanked the public for their support: "Thank you for all your kind messages after the fire on Necker. We're thankful that everyone is ok."
Branson said the house was "completely destroyed" and the cause of the fire was still being investigated, but lightning was likely to blame. He told the AP, "My office was based in the house and I have lost thousands of photographs which is very sad." He also vowed to rebuild the house "as soon as we can."