Yet as Rita lost steam after hitting land before dawn, a storm of criticism gathered over the messy evacuation of nearly three million people that highlighted lingering weaknesses in the US response to disasters.

Rita rammed the coasts of Texas and Louisiana bristling with vital oil and chemical installations at 3:39 am (0739 GMT), unleashing a fearsome torrent of rain and winds howling at 195 kilometers per hour.

But within seven hours it had faded from a dangerous category three to a minimal category one on the Saffir-Simpson scale, leaving the cities of Houston and battered New Orleans largely unscathed and other communities counting their blessings.

"I expected the storm to be a heck of a lot worse," Brandon Allen, 32, a realtor in Port Arthur, said after surveying the damage in this coastal inlet city in an all-terrain vehicle.

Louisiana officials reported no deaths or injuries from Rita. No new casualties were reported in Texas beyond 24 elderly people killed in an explosion aboard a fleeing bus Friday and an aged woman who succumbed to heat exhaustion.

But Rita still produced scenes of mayhem along a stretch of the southern US coast weary and bloodied by Katrina's fury last month that left at least 1,075 people dead and hundreds of thousands homeless.

Street signs, roofing, and other debris careened through the air and windows were smashed. Deluged streets were littered with downed powerlines and traffic lights and fires were quickly spread by fast-moving winds.

Half a million people were reported to be without power in Houston alone.

Much of Port Arthur, a key oil industry center, was cut off by waist-high floodwater and downed powerlines. Cars lay smashed beneath uprooted trees and the main refinery -- a major employer for the town's 56,000 people -- was out of reach.

In Galveston, Texas, where a 1900 hurricane killed up to 12,000 people, a fierce blaze turned the historic district into an outdoor furnace spitting out walls of flame and embers towards firefighters.

In Beaumont, Texas, just northwest of the spot where Rita crashed ashore from the Gulf of Mexico, flashes of green light erupted in the night sky as electricity substations short-circuited, plunging whole towns into darkness as the storm wailed.

Forecasters warned fearsome flood tides of up to 15 feet high (4.5 metres) could swallow up parts of the Gulf Coast amid signs the storm could stall for days over land and swamp it in rain.

Walls of water surged through the streets of Lake Charles, 55 miles (88 kilometers) to the east, across the state line in Louisiana, as buildings sustained heavy damage, television reports said.

In New Orleans, levees were breached Friday on the Industrial Canal and the water was eight feet (2.4 meters) high in some areas, including the impoverished Ninth Ward and St Bernard's Parish -- two of the areas worst hit by Katrina.

Chastened by criticism of the slow response to Katrina, the authorities went all out to prepare for Rita, putting troops, helicopters and trucks on standby and readying supplies of food, water, ice and propane.

But they came in for new criticism over the operation to evacuate nearly three million people that became bogged down in massive traffic jams and fuel shortages that forced some to abandon their cars.

Houston Mayor Bill White called the situation "totally unacceptable" and major newspapers railed that lessons from the lack of sufficient preparedness for Katrina had gone unlearned.