By Elinor Shields
Images from the stricken city of New Orleans show that many of those suffering in its streets and shelters are black and poor.
Many of those stranded did not have the resources to flee
The plight of those stranded amid the filth and the dead has highlighted a side of the city most tourists did not see - one in which two-thirds of its residents are black and more than a quarter live in poverty.
Anger is mounting among African-American leaders that this section was left behind when others fled.
Some say the chaos in Katrina's aftermath has exposed deep divisions in both the city and US society.
"We cannot allow it to be said by history that the difference between those who lived and... died... was nothing more than poverty, age or skin colour," Congressman Elijah Cummings said.
'Paycheck to paycheck'
Correspondents say New Orleans' glamorous reputation has always concealed a high level of deprivation.
10 times national murder rate
21% of households without access to a car
The city famous for its jazz clubs and horse-drawn carriage rides was also a place in which about one in three children lived in poverty, in one of the poorest states in the country.
Observers say this group was particularly vulnerable in the face of a hurricane.
Many of those trapped by Katrina's floodwaters lived in dilapidated neighbourhoods that were long known to be exposed to disaster if the levees failed.
And a large number would have had no means to flee the region as the storm loomed - a recent US census found that one-fifth of the city's residents had no access to a car.
"We don't have transportation," one resident told WHBF-TV. "We're living paycheck to paycheck, it's not like we're just able to get up and leave."
A former leader of the black caucus in the House of Representatives agrees.
"It is one thing to receive a warning to get out - it's something else to have the ability to get out," Congressman James Clyburn said.
Black members of Congress have also criticised the pace of relief efforts.
Some say the response was slow because those most affected are poor.
"I'm ashamed of America. I'm ashamed of our government," Congresswoman Carolyn Kilpatrick said.
"George Bush doesn't care about black people," rapper Kanye West told viewers of an NBC benefit concert for hurricane victims.
Other commentators object to the media's handling of the crisis.
"Television is creating a sympathetic image of white people fleeing, and black people caught up in a shoplifting orgy," Lawrence Aaron wrote in New Jersey's Record.
But some hope that the aftermath of the hurricane will force people to confront the issue of inequality.
"Most cities have a hidden, or not always talked about, poor population, black and white, and most of the time we look past them," Spencer Crew, the chief of a Cincinnati civil rights centre, told the New York Times.
"This is a moment in time when we can't look past them. Their plight is coming to the forefront now," he said.