American Airlines has announce it will wave change fees for passengers affected by Hurricane Irene. This allows passengers to rebook their flights to specific location from specific dates.

Flights from these locations can be rebooked.
La Romana/Casa de Campo, Dominican Republic (LRM)
Port-au-Prince, Haiti (PAP)
Puerto Plata, Dominican Republic (POP)
Punta Cana, Dominican Republic (PUJ)
San Juan, Puerto Rico (SJU)
Santiago, Dominican Republic (STI)
Santo Domingo, Dominican Republic (SDQ)
St. Croix, U.S. Virgin Islands (STX)
St. Thomas, U.S. Virgin Islands (STT)
Tortola, Beef Island, British Virgin Islands (EIS)

These are the applicable dates.
Tickets Issued on/before: August 21, 2011
Ticket Travel Dates: August 21 – 24, 2011
New Travel Date: August 21 – 27, 2011

There are also provisions for those who would like to change their origin or destination locations. For full details check this American Airlines page. Tropical Storm Irene Travel Notice