An initial explosion sent flames of red and orange shooting into the pre-dawn sky. A series of smaller blasts followed and then acrid, black smoke that could be seen even in the dark. The vibrations were felt all the way downtown.
The explosions appeared to originate close to the east bank of the Mississippi River, near a residential area and rail tracks. At least two police boats are at the scene.
President Bush is to visit the hurricane zone today - first Mississippi and Alabama, and then New Orleans, where the situation continues to grow more desperate, with police reporting some refugees being raped and beaten.
First lady Laura Bush will travel separately to the area devastated by Hurricane Katrina, and will be meeting face to face with refugees in Lafayette, Louisiana.
Some who fled New Orleans' floodwaters for what they thought would be the safety of the Superdome or the city's Convention Center have found death instead.
At least two bodies are in plain sight at the Convention Center.
Flood victims desperate not to share that fate have been trying to get onto scare buses to take them out of town - at the Superdome and the Convention Center, and on a highway several miles away: standing, watching, and hoping against hope.
One place they won't be going is the Astrodome: it filled up overnight, and newly arriving refugees will be sent to other shelters in Texas.
"This is a desperate SOS," said New Orleans Mayor C. Ray Nagin, as he described deteriorating conditions in the city that only a few days ago fondly called itself the "Big Easy."
Fights and fires have broken out, looting continues to be a problem, corpses lie out in the open, and rescue helicopters and law enforcement officers have been shot at as the more than 80 percent flooded city spirals into increased anarchy.
The governor declared war on looters who have made the city a menacing landscape of disorder and fear.
"They have M-16s and they're locked and loaded," Gov. Kathleen Blanco said of 300 National Guard troops who landed in New Orleans fresh from duty in Iraq. "These troops know how to shoot and kill, and they are more than willing to do so, and I expect they will."
Thursday, President Bush harkened back to the U.S. response to the tsunami when he asked his father, former President George H.W. Bush, and former President Clinton to lead a private fund-raising campaign for victims, as they did in South Asia last winter.
"This is an agonizing time for the people of the Gulf Coast," Mr. Bush said Thursday as he stood with the two former presidents in the White House and urged patience, .
Late Thursday night, the Senate approved $10.5 billion in relief aid for victims of Hurricane Katrina.
Anger mounted across the ruined city, with thousands of Hurricane Katrina victims increasingly hungry, desperate and tired of waiting for buses to take them out.
"We are out here like pure animals. We don't have help," the Rev. Issac Clark, 68, said outside the New Orleans Convention Center, where corpses lay in the open and the and other evacuees complained that they were dropped off and given nothing — no food, no water, no medicine.
CBS News Correspondent Lee Cowan reports that in the heart of New Orleans' medical district, some of the most decorated hospitals in the country have become islands of desperation.
"We're down to one day's rations… That's all we have," Dr. Steven Morse of LSU told Cowan.
About 15,000 to 20,000 people who had taken shelter at the convention center to await buses grew increasingly hostile. Police Chief Eddie Compass said he sent in 88 officers to quell the situation at the building, but they were quickly beaten back by an angry mob.
"We have individuals who are getting raped, we have individuals who are getting beaten," Compass said. "Tourists are walking in that direction and they are getting preyed upon."
In hopes of defusing the unrest at the convention center, Mayor Ray Nagin gave the refugees permission to march across a bridge to the city's unflooded west bank for whatever relief they can find. But the bedlam at the convention center appeared to make leaving difficult.
Meanwhile, officials declared a public health emergency along the due to unsafe drinking water, and surveyors say the town of Waveland, 35 miles from New Orleans, was completely obliterated by Hurricane Katrina.
National Guardsmen poured in to help restore order and put a stop to the looting, carjackings and gunfire that have gripped New Orleans in the days since Katrina plunged much of the city under water.
Although more Guardsmen are on the way, CBS News Correspondent John Roberts reports that there's still a surprising lack of force on the ground and the mayor fears the city will be gripped by anarchy.
CBS News National Security Correspondent David Martin reports that with 40,000 National Guard troops already called up for duty, the Army is making preparations to send in as many as 10,000 combat troops from the active duty force.
In a statement, Nagin said: "This is a desperate SOS. Right now we are out of resources at the convention center and don't anticipate enough buses. We need buses. Currently the convention center is unsanitary and unsafe and we're running out of supplies."
Homeland Security Secretary Michael Chertoff said the government is sending in 1,400 National Guardsmen a day to help stop looting and other lawlessness in New Orleans. Already, 2,800 National Guardsmen are in the city, he said.