[PHXFlyer]

This incident was in the news. There was no loss of cabin pressure. The sudden drop in altitude was so that they would no longer require cabin pressure which may have accelerated a fire if there was one. According to the crew the masks were never deployed. Panicked passengers forced the compartments open. If there is smoke in the cabin oxygen could turn a slow burn into an inferno very quickly.

As far as not being informed of where they were landing I'm sure they were told once on the ground. Once an emergency is declared only essential announcements are made from the flight deck. The only announcement made to the passengers on US Airways flight 1549 was "brace for impact."

As for the communication issues once on the ground, you must realize that Spirit does not fly into Daytona. There's no ground staff at all. According to the news reports the station manager from Ft. Lauderdale drove up to Daytona to handle the situation. Having a disabled aircraft divert to an airport that an airline doesn't serve must be a logistical nightmare. I'm sure Spirit was considering bus service but they were somehow able to pull a spare aircraft and crew from somewhere to do the job instead. Additionally the airport arranged food and beverages forthe stranded passengers.