At least six people are dead (and the toll is expected to rise), homes, schools and even the famous airport are destroyed, looting has been reported, and the cafes and shops of the French seaside village of Marigot are submerged in flood waters.
On the northwestern French side of the island, Trump owns the Chateau des Palmiers, a sprawling 11-bedroom vacation villa he's trying to sell (only $16.9 million, price reduced from $28 million last week).
But already-wary buyers might be more so after Irma. Meanwhile, another storm, Hurricane Jose, is on a path to possibly hit the island with more damage this weekend.
The current state of Trump's villa, located on Plum Beach in the plum Terres Basses enclave of luxury vacation villas, is as yet unknown. But the American owners of another villa just above his, Villa Mille Fleurs, reported severe, but not catastrophic, damage to their house, in an email to USA TODAY.
The initial reports coming out of St. Martin (and other Caribbean islands) have been dire: The western French side was 95% destroyed, according to The Guardian and other reports, quoting a Radio Caribbean International interview with a local government official, Daniel Gibb.
"It's an enormous catastrophe," Gibb said. "Ninety-five percent of the island is destroyed. I'm in shock. It's frightening."
On the Dutch side, William Marlin, the Sint Maarten prime minister, predicted a serious housing shortage and a lost season for the tourism the island depends on, according to the Associated Press.
"We foresee a loss of the tourist season because of the damage that was done to hotel properties, the negative publicity that one would have that it's better to go somewhere else because it's destroyed — so that will have a serious impact on our economy," he said in an interview.
Judging from history, Mar-a-Lago should fare better, having weathered four major hurricanes with little damage in the 90 years since cereal heiress Marjorie Merriweather Post built the 126-room, 62,500-square foot mansion. At the time, it cost them $5 million — the equivalent of almost $70 million today.
Trump bought the then-dilapidated property in 1985 for $10 million, and spent millions more refurbishing it before turning it into a club in 1995. It's become an unofficial winter White House: After his inauguration, he and his family spent multiple weekends at the estate; he even hosted foreign leaders there.
It's located on a narrow barrier island, flanked by the Intracoastal Waterway and the Atlantic Ocean, but its walls are 3-feet thick, anchored by steel and concrete beams embedded into coral rock. On Friday, shutters could be seen covering some of the mansion's windows.
"It's the safest place in the world for a hurricane," said Anthony Senecal, Trump's longtime butler and Mar-a-Lago's unofficial historian, in an interview with The Associated Press last year. "That house ain't going nowhere. That house has never been seriously damaged."
Jeff Masters, director of the Weather Underground forecasting service, said Thursday that the biggest threat to Mar-a-Lago will likely be a storm surge reaching as much as 8 feet, putting low-lying areas at peril causing some water damage to the main buildings.