Looting in New Orleans

This story makes you absolutely sick. In the midst of a natural calamity, you have goons looting stores around the city. At first I thought they were out looking for food and water, which one can understand. But they also seem to be stealing guns. There are reports of armed gangs firing at rescuers. Why? I can't get it! You'd think people would be suffused with a wave of human compassion and be out looking to help their fellow brethren. When the floods hit Bombay, India and brought that city to a standstill in July, there were stories of people helping each other out. No one was out shooting and firing their guns. This behavior is baffling. Why would anybody fire at rescue helicopters? Because they got their late? I don't understand the reaction.