The answer to my question

In my last post, I asked why private relief efforts weren't more evident in New Orleans early on, when adequate government resources had not yet arrived. Don Boudereaux at Cafe Hayek has the answer, and it's exactly what I had suspected. They weren't allowed in.

According to the Disaster FAQs section of the American Red Cross's website:

Hurricane Katrina: Why is the Red Cross not in New Orleans?

• Access to New Orleans is controlled by the National Guard and local authorities and while we are in constant contact with them, we simply cannot enter New Orleans against their orders.
  
• The state Homeland Security Department had requested--and continues to request--that the American Red Cross not come back into New Orleans following the hurricane. Our presence would keep people from evacuating and encourage others to come into the city.
  
• The Red Cross has been meeting the needs of thousands of New Orleans residents in some 90 shelters throughout the state of Louisiana and elsewhere since before landfall. All told, the Red Cross is today operating 149 shelters for almost 93,000 residents.

Boudereaux also points to this Knight-Ridder report that the Red Cross wasn't alone in being denied access to the city.

As federal officials tried to get some control over the deteriorating situation in New Orleans, chaos was being replaced with bureaucratic rules that inhibited private relief organizations' efforts.

"We've tried desperately to rescue 250 people trapped in a Salvation Army facility. They've been trapped in there since the flood came in. Many are on dialysis machines," said Maj. George Hood, national communications secretary for the relief organization.

"Yesterday we rented big fan boats to pull them out and the National Guard would not let us enter the city," he said. The reason: a new plan to evacuate the embattled city grid by grid - and the Salvation Army's facility didn't fall in the right grid that day, Hood said in a telephone interview from Jackson, Miss.