* Woman killed, flooding widespread in Houston
* Over 1,000 rescued as floods trap people in homes, cars
* Hospital evacuated, airports shut
* Houston residents told to climb on roof if homes flood
* Storm Harvey hit Texas as Category 4 hurricane late Friday (Updates with additional details on storm, comments from Tex Gov Abbott, adds quotes)
HOUSTON, Texas, Aug 27 (Reuters) - Emergency crews raced to pull people from cars and homes as flood waters rose across southeast Texas on Sunday, rescuing over 1,000 people around Houston as Tropical Storm Harvey hit the region with "unprecedented" rain expected to last for days.
Harvey came ashore late Friday as the most powerful hurricane to hit Texas in more than 50 years and has killed at least two people. The death toll is expected to rise as the storm lashes the U.S. state for days, triggering record floods, tidal surges and tornadoes.
The storm has caused chest-deep flooding on some streets in Houston as rivers and channels overflow their banks. More than 25 inches (64 cms) of rain has fallen in some parts of the city, with the storm expected to dump a further 12 to 25 inches (30-63 cms) over the next few days, the National Weather Service forecast.
The total could reach 50 inches in some coastal areas of Texas by the end of the week, or the average rainfall for an entire year. Scenes of submerged highways and flooded homes in the nation's fourth-largest city recalled the devastation that struck New Orleans during Hurricane Katrina in August 2005.
"This event is unprecedented and all impacts are unknown and beyond anything experienced," the government's National Weather Service said on Twitter. The center of Harvey was still 125 miles away from Houston, and was forecast to arc slowly toward the city through Wednesday. Harvey was downgraded to a tropical storm on Saturday because its winds had slowed, but days of torrential rain are forecast. Texas Governor Greg Abbott, in a press conference, said new tornado warnings are expected later on Sunday.
The storm struck at the heart of the country's oil and gas industry, forcing operators to close several refineries and evacuate and close offshore platforms. The Gulf is home to about nearly half of the nation's refining capacity, and the reduced supply could affect gasoline supplies across the U.S. Southeast and other parts of the country.
The swift rise of flood waters surprised authorities and Houston residents with boats were asked to help with rescues. Emergency services told the city's 2.3 million inhabitants to climb onto the roofs of houses, if necessary, to escape the water. People in Houston and other areas of Texas were asked not to leave their homes, even if they flooded, as roads were impassable.
"We've already had 20 helicopters in the air to help with rescue missions," said Abbott.
The Ben Taub Hospital in Houston's Medical Center was being evacuated on Sunday. An American Red Cross emergency shelter was forced to shut due to flooding and the group opened two more, including one in a convention center in downtown Houston.
"Within less than a half hour, we had 7 to 8 inches of water in our first floor," said Brian Hoskins, 25, a petroleum engineer who lives in Houston.
Many people were stuck in vehicles on raised highway sections with dips in the roads ahead of them flooded.
The Twitter account of the sheriff of Harris County, which includes most of Houston, was inundated with rescue requests and his team were unable to respond quickly to all of them.
"All agencies care but everyone simply operating at maximum capacity," Sheriff Ed Gonzalez tweeted at one point.
Houston's Bush International and William P. Hobby airports canceled all commercial flights on Sunday. Hobby had standing water on the runway and said the arrivals area was flooded.
"There are a number of stranded people on our streets, calling 911, exhausting needed resources. You can help by staying off the streets," Houston Mayor Sylvester Turner said on Twitter.
On Friday night, a man died in a house fire in the town of Rockport, 30 miles (48 km) north of Corpus Christi. The second confirmed fatality came on Saturday when an elderly woman drowned attempting to drive through flooded streets in west Houston, said city police Sergeant Colin Howard.
Millions of barrels per day of fuel production have been halted, and gasoline prices rose ahead of the storm. Benchmark gasoline futures were likely to rise again as shutdowns extended from to the refining hub of Houston, including Exxon's Baytown refinery, the second largest U.S. refinery.
HARVEY THREATENS RECORD RAIN
Harvey slammed into Texas as a Category 4 hurricane with winds of 130 miles per hour (210 km per hour), making it the strongest storm to hit the state since 1961. It threatens to break a record established when Alvin, Texas, was deluged by 43 inches of rain in 24 hours on July 24-25, 1979.
The storm ripped off roofs, destroyed buildings, flooded coastal towns and had cut off power to about 280,000 people in Texas as of Sunday.
Abbott said 1,800 members of the military would help with the statewide cleanup. Another 1,000 people were conducting search-and-rescue operations.
The size and strength of Harvey dredged up memories of Katrina, the 2005 hurricane that killed 1,800 in a disaster made worse by a slow government emergency response.
U.S. President Donald Trump, facing the first big natural disaster of his term, said on Sunday he would visit the area as soon as he could do so without causing more disruption. Trump signed a disaster proclamation on Friday, triggering federal relief efforts. Abbott said 50 counties have been declared state disaster areas.
Jose Rengel, a 47 year old construction worker who lives in Galveston, was helping with rescue efforts in Dickinson, Texas, southeast of Houston, where he saw water cresting the tops of cars.
I am blessed that not much has happened to me but these people lost everything. And it keeps raining," he said. (Additional reporting by Brian Thevenot in Corpus Christi, Sophia Kunthara, Sophia Kunthara and Chris Michaud in New York, Timothy Gardner in Washington, D.C., Erwin Seba, Ruthy Munoz, Marianna Parraga, Ernest Scheyder and Gary McWilliams in Houston; Writing by Dan Whitcomb and Simon Webb; Editing by Andrea Ricci and Andrew Hay)