I had tickets on Delta for September 9th through the 16th. When Irma struck I called them to cancel and they gave me a credit because Delta had not officially cancelled the flight. On September 8th I received an email from Delta advising flight 908 from ATL to SXM was cancelled. I called Delta as soon as I got that email and they gave me a full refund. I am assuming that once they admit the flight will be cancelled they will agree to refund. I also called the travel insurance company and received a full refund from them which I believe it was because it was a Delta initiated cancellation.