A new update from U.S. Govt.: (note: flights leaving as early as 8:30 a.m. !)

"Planned Flights for Wednesday, September 13:
Bring your passport and travel documents to the airport if you have them. U.S. citizens may still proceed to the airport for processing if you no longer have your documents.

Dutch St. Maarten: Several flights are planned to fly out of St. Maarten on Wednesday morning, September 13, by 0830. Flights will be boarded on a first come, first serve basis. U.S. citizens are advised to arrive at the airport as early as is safe to do so. We discourage U.S. citizens from traveling in the dark. Only service animals will be permitted to board the flights. Please note, passengers arriving at St. Maarten Airport should expect long wait times. There is no running water at the airport and very limited shelter.

The flights will travel from St. Maarten to San Juan, Puerto Rico. Onward travel arrangements from San Juan will be the responsibility of the traveler. We encourage you to closely monitor our Hurricane Irma Crisis Page for important updated information on available flights, and the operating status of U.S. embassies in the region."

https://cw.usconsulate.gov/notice-u-s-citizens-aftermath-hurricane-irma-sitrep-9/