As far as I know (and I could very well be wrong), it takes a special type of helicoptor to bring in water, or a copter with a special container hanging underneath. The local authorities have been trying to take care of it, but in some cases right now it might be better to let something burn now instead of demolish it later.
Just a thought.
And I'd heard of people shooting at the rescuers, too. That's why they had to stop boat and other evacuations for a time. You'd think that the snipers would allow those who want to get out of the city get out.