This is now prominently posted on the home page of US Air's web site:
Due to circumstances in Belize, US Airways has relaxed its travel policies for passengers whose travel may be affected. For the latest flight details, please check your flight and gate information.
These re-accommodation procedures are available to passengers ticketed from April 21-24 2005.
For flights originally scheduled for this time period, US Airways will waive the standard change fee, advance reservation or ticketing requirements.
The entire itinerary can be moved forward or delayed, up to fourteen days from the scheduled origination date. The length of the trip cannot be changed.
Full value of wholly unused tickets can be applied toward the purchase of a ticket to an alternate destination, with travel to originate within seven days of the scheduled origination date.