2,000 evacuated as Tropical Storm Harvey lashes HoustonLast updated on Aug 28, 2017, 10:28 am
Hurricane Harvey has weakened to a tropical storm.
Yet, it continues to batter Houston, Texas, America's fourth largest city, with record rainfall causing catastrophic flooding.
Over the past 24-hours, parts of Houston witnessed 22-inches of rain. Nearly 2,000 people were rescued from flooded areas in and around Houston.
There are reports of possible deaths but the actual death toll remains unconfirmed.
Harvey most powerful storm to hit US in 13 years
Harvey is the most powerful storm to hit America since Hurricane Charley in August 2004. It's also the strongest storm to hit Texas since 1961's Hurricane Carla, which left 34 people dead, the Houston Chronicle has reported.
Rising flood waters push people to rooftops, rescue efforts hampered
Thousands of people were forced onto their rooftops or to seek higher ground to escape rising waters.
Rescue workers struggled to deal with the constant calls for help. Authorities have requested residents to only call 911 if their lives faced an imminent threat.
Strong winds hampered rescue efforts even as thousands remained without power.
The coast guard has requested additional helicopters.
Houston facing most devastating floods in history
"What we're seeing is the most devastating flood event in Houston's recorded history. We're seeing levels of rainfall that are unprecedented," said chief meteorologist at reinsurance firm Aon Benfield, Steve Bowen.
"Historic flooding" in Houston to continue
President Donald Trump will be visiting Texas on Tuesday, August 29.
The National Weather Service (NWS) said Houston will receive around 40-inches of rainfall while some areas could receive over 50-inches.
The NWS said south-east Texas, including Houston, faced the threat of "significant to catastrophic flash flooding."
"Historic flooding is expected to continue in the Houston metropolitan area through the foreseeable future," it added.