(CNN) -- A lightning strike sparked a fire Monday that destroyed the Caribbean island home of Virgin Group Chairman Richard Branson, a statement from the media mogul said.

About 20 people, including Oscar-winning actress Kate Winslet, were in the house at the time of the fire, which broke out around 4 a.m., Branson said. No one was injured.

"Many thanks to Kate Winslet for helping carry my 90-year(-old) mum out of the main house to safety," Branson wrote in the e-mailed statement.

Branson said the house, located on Necker Island, the 74-acre private island the billionaire owns in the British Virgin Islands, was destroyed, along with "thousands of photographs and my notebooks."

"But all my family and friends are well -- which in the end is all that really matters," he said.

The lightning strike that caused the fire occurred in the midst of Tropical Storm Irene, which strengthened into a hurricane early Monday.

Pictures show the house completely engulfed in flames against an ominous sky.

"Currently just huddled up with family and friends in the continuing tropical storm realising what really matters in life," Branson said.

He promised to rebuild, saying "we'll create something even more special out of the ruins."

In addition to Branson's private residences on the island, Necker is also open as a luxury resort that can accommodate up to 28 guests for those who can afford the hefty $54,500-a-night price tag.

The island has been featured on such TV programs as "MTV Cribs," and TV personalities Nick Lachey and Vanessa Minnillo were recently married on the island.