Let's be clear with the correct terminology here. According to their own disaster plan, the word "shelter" was a facility out of the flood area that was stocked with food and water. They never made it that far.
Instead, the inhabitants of New Orleans were forced to stand in line for hours at a facility that was supposed to be used as a "staging area" to bus them out to the "shelters."
Once the evacuation routes became impassable, then and only then would the "staging area" (the Superdome) become a "refuge of last resort."
All the satellite photos of the flooded buses tell the story. They didn't follow their own plan.
That wasn't my quote by the way.
But yes, the buses weren't utilized to evacuate the poor, and they ended up at the Superdome, which wasn't prepared to take them.
The same thing happened last year with Ivan and in 98 with Dennis(?).