"Looting" is when people take things WITHOUT permission. This isn't looting. And if firefighters and National Guard personnel are taking things that have been offered by the owner, they are most likely taking them to use in their efforts to help people. They're better equipped than most people to distribute the items to where they're most desperately needed.
The riot/stampede, however, was predictable. This happens all to frequently at stores which have simply offered a deal like wedding dresses for $100. I'm sure Wal-Mart meant well, but they would have done better to just invite uniformed emergency workers to take whatever they needed -- not the whole population.
FNC said the FF and Guardsmen were detailed to keep order for the giveaway, but just joined in when things broke down.