Hurricane Rita is expected to destroy almost 5,700 homes and affect more than five million Texans when it slams into the US coast overnight, officials said.
Jack Colley, the state’s emergency management coordinator, predicted that the city of Port Arthur would be submerged in 20 feet of water and at least 16,000 people made homeless across Texas.
“We could expect probably sustained hurricane winds, beginning at midnight tonight, for 16 hours, an incredible storm,” he said.
As Rita headed towards land, water again began gushing into the Louisiana city of New Orleans, swamping its Lower Ninth Ward – an area devastated by Hurricane Katrina less than four weeks ago.
“Our worst fears came true,” said Major Barry Guidry of the Georgia National Guard which is assisting with relief efforts. “We have three significant breaches in the levee and the water is rising rapidly.”
Port Arthur Mayor Oscar Ortiz said the winds were starting to pick up heavily but that 95% of the city had been evacuated.
A mandatory curfew was called for the few remaining in the city of 58,000.
Rita weakened to a Category 3 storm as it edged towards land, packing winds of 125mph.
Louisiana Governor Kathleen Blanco warned residents to get to the highest places they could.
“We are ready to respond with helicopters and heavy equipment,” she said.
The damage is expected to top $8.2bn.
President George Bush had expected to travel from Washington to Texas, his home state, as the storm closed in, but his plans were cancelled because of the storm.
“Our job is to prepare for and assist state and local people to save lives and help these people get back on their feet,” he said at the Pentagon.
David Paulison, acting head of the Federal Emergency Management Agency (FEMA) said 400 medical personnel were on stand-by in Texas with lorry-loads of food, water and ice.
At least 17 urban search and rescue teams are on the ground along with 50,000 regular and national guard troops.
“I hope everyone’s listening to the warnings,” he said. “It’s going to be a few days before the first respondents can get in there.
“Don’t return to your homes, stay away from power lines, stay in place until we tell you it’s safe. We are going to make sure that you get taken care of.”
Tragedy struck earlier today when a bus carrying around 45 elderly evacuees out of Houston to Dallas exploded, killing at least 24 people.
Early reports suggested mechanical problems sparked a fire causing passengers’ oxygen tanks to explode.
The vehicle was engulfed in flames, causing a 17-mile tailback on the busy interstate highway.
The driver reportedly survived the blast and repeatedly got back on the bus to try and rescue passengers.
Texas Governor Rick Perry said 2.7 million people had fled the coast and that evacuations were a success despite “excruciatingly slow” traffic.
“It’s a great test for the people of this state, for emergency management, homeland security the military,” he said.
“But we are going to get through this and we have prepared with extensive exercises. We are going to get through it because our residents took this threat seriously.
“Be calm be strong, say a prayer for Texas.”
Major oil refineries have been shut down amid fears that petrol prices would soar.
The Salvation Army is on stand-by in Texas with 38 mobile canteens fully stocked and ready to launch relief operations as soon as the storm has passed.
Staff in Houston have been helping with evacuation efforts and have set up two of their own shelters to accommodate those who did not want to leave.
Major JR Jones said dark clouds had formed over the city and the streets were deserted.
“There is nothing here except a few police patrols,” he said. “It’s like all life has evaporated.”
Most of those taking refuge in the shelters are elderly or just did not want to venture too far from their homes.
“Everyone’s nervous,” Major Jones said. “Most people get a little anxious when they leave their homes, but we’re all here and we’re ready to sit it out.”