Come come now. In Haiti, a machete is like a pocketknife. And it looks to me like a lot of the "looting" is a lot like scavenging and is a matter of surviving and making use of what is available...
Crisis and chaos also equals "opportunity" in many people's minds.
The country was hit by a major earthquake, yes. But I've seen the videos, and not every building collapsed (far from it) -- it seems mainly the multi-story "fancy" buildings in the downtown areas (ones with government officials, UN people, etc).
Even if the statement that 100,000 or more may be dead -- in a country of 10 MILLION that constitutes about 1% of the population, and even if injuries are tenfold greater than that, it would still leave 90% of the population relatively unharmed.
If, as is very likely, there were certain areas of the capitol city that were harder "hit" by the earthquake -- then that also means that
other areas were LESS damaged and suffered fewer casualties.
And it WASN'T flooded like New Orleans, nor a Tsunami like Indonesia suffered -- so majority of their food should still be intact, and likewise with their water supply (it's probably NOT in good condition, but then it wasn't before the quake either).
Long story short -- this isn't some BLACK PLAGUE where 1/2 of the population dies suddenly. Yes its another disaster, but Haiti seems to go through one or another of them every 5 years or so (the place is a frigging mess, but that has been true for centuries).