"I have never seen anything like this hurricane. Necker and the whole area have been completely and utterly devastated," Richard Branson wrote

Hurricane Irma destroyed much of Richard Branson’s private island in the Caribbean, and the billionaire is opening up about surviving one of the most powerful storms in history while hunkered down in his wine cellar.

“I have never seen anything like this hurricane. Necker and the whole area have been completely and utterly devastated. We are still assessing the damage, but whole houses and trees have disappeared,” Branson wrote in a blog post using a satellite phone from Necker Island, which he has owned since 1978. “Outside of the bunker, bathroom and bedroom doors and windows have flown 40 feet away.”

“All of the team who stayed on Necker and Moskito during the hurricane are safe and well,” he continued. “We took shelter from the strongest hurricane ever inside the concrete cellar on Necker and very, very fortunately it held firm. Our thoughts go out to everyone affected by the disaster elsewhere in the BVI, Caribbean and beyond.”

Branson’s son, Sam, posted pictures of the devastation to his Instagram account, which show buildings and homes ripped apart by Irma’s 185-mph winds.

“Very concerned for our friends and everyone on the neighboring islands and people in its path,” Sam wrote in an Instagram post. “Please don’t take this hurricane lightly if it is heading your way. If your building is not very solid, do find somewhere safe! Homes can be rebuilt but lives can’t.”

Branson also warned others in the path of the storm to seek shelter and prepare for the worst.

Branson wrote earlier this week that he would stay on Necker Island and take shelter in his wine cellar with a group of Virgin employees. Branson posted pictures of staff sleeping in makeshift beds and playing dice as the storm approached. The Virgin founder said he had experienced three hurricanes over 30 years on the island, and planned to wait out Irma since his home was reinforced to withstand high winds.

Unfortunately, the rest of the Necker and the surrounding islands did not have such reinforcement.

“I know we are fortunate here on Necker and Moskito. Our wonderful team are fine,” Branson wrote. “I know we will all band together and rebuild the islands to become stronger and even more wonderful than they were before.”

Branson announced Virgin had made a donation to the British Red Cross to support relief efforts. “I would urge everyone to donate to the British Red Cross through Virgin Money Giving (who are waiving their fees in support of the appeal) to help local communities,” he said.

Hurricane Irma is now closing in on South Florida and is expected to make landfall Sunday morning.