Anyone who MIGHT FOR ANY REASON have a need to leave the US in a hurry - should get their US Passport and keep it up to date and renewed. The renewal by mail works well (normally) and can be done in a week or ten days. Rush and emergency service is available although the emergency issue service can cost you up to 500 for getting same day issuance at a passport issuing office like LA, NY or DC. I don't know if Miami still can issue passports or not. They could once but today, who knows?

For emergency issue you need:

Proof of the emergency (ie a telegram or email from an ill relative will do)
Your plane ticket (preferred) or Reservation proof if you don't have the ticket yet.
The usual proof of citizenship stuff to get a passport.
if it's just a renew of your old passport, then you'll need the old one and the right forms.

If you are in those "issuing cities" you can call, get an appointment and often get it issued while you wait. If you're not in those cities, then everything has to be fedexed in and out and of course you loose a minimum of 2 days with FEDEX best services.