Days after Katrina: Rights Violated?

I was in New Orleans during Katrina (i lived there) and I have a question about the government's right to detain people in a situation such as Katrina.

Basically long story short, me and my room mate at the time were attempting to leave the city four days after the storm. There was as far as we knew only one main bridge going out of the city. This bridge was basically blocked off by military personnel holding fully automatic weapons and standing in front of armored vehicles. We were fully capable and prepared to walk however far to get to some form of safety. We really just wanted to extract ourselves from the increasingly violent and dangerous situation.

Instead we were told at gun point that we had to return to the city, and thus were effectively detained in New Orleans. Had we resisted, and tried to leave, we would have been arrested or shot.

Did anyone have the right to tell us we were unable to leave the city? If not, what rights of mine were violated?

Thanks in advance!

Thats messed up.I guess its what "Alex jones" calls it prison planet.I could see letting no one enter,but no one leave is a different story

I asked an ex-military friend of mine about Marshal Law, and he said it was within the legal rights of the National Guard to detain us in the city during Martial Law, but at any other time would have been illegal.