I was in a minor fender bender once in Pittsburgh and went through the trouble of calling the local police dept. They said you have to call 911 (which I initially didn't since the damage was only to two cars, and I had only called because the other driver wanted the police involved). I called 911 and they said it's the right place to call but they aren't coming out since no one was hurt. And that was that.

I think calling 911 is appropriate as a clearinghouse is appropriate, just don't dilly dally. If I was on that plane, at about the one hour mark I'd probably start calling Delta and seeing what they would say. At the two hour mark I'd call my travel agent and company and see if they can do anything. And at three hours I'd probably have a friend find the number for the airport management and call them... I don't know if I would have thought of calling 911 as a hostage, but I guess in 9 hours you have a lot of time to think about your options!