A woman uses a coat hanger to try and retrieve an item from a destroyed house after Hurricane Harvey struck Fulton, Texas, August 26, 2017.

U.S. President Donald Trump planned to visit Texas on Tuesday to survey the response to devastating Tropical Storm Harvey, the first major natural disaster of his White House tenure.

The slow-moving storm has brought catastrophic flooding to Texas, killed at least nine people, led to mass evacuations and paralyzed Houston, the fourth most-populous U.S. city.

Crews overwhelmed by thousands of rescue calls during one of the heaviest downpours in U.S. history have had little time to search for other potential victims, but officials acknowledge the grim reality that fatalities linked to Harvey could soar once the devastating floodwaters recede from one of America's most sprawling metropolitan centers.

More than three days after the storm ravaged the Texas coastline as a Category 4 hurricane, authorities had confirmed only three deaths — including a woman killed Monday when heavy rains dislodged a large oak tree onto her trailer home in the small town of Porter. But unconfirmed reports of others missing or presumed dead were growing.

"We know in these kind of events that, sadly, the death toll goes up historically," Houston police Chief Art Acevedo told The Associated Press. "I'm really worried about how many bodies we're going to find."

The storm has also roiled energy markets and caused damage estimated to be in the billions of dollars, with rebuilding likely to last beyond Trump's current four-year term in office.

"My administration is coordinating closely with state and local authorities in Texas and Louisiana to save lives, and we thank our first responders and all of those involved in their efforts," Trump told reporters at the White House on Monday.

Trump was scheduled to arrive on Tuesday morning in Corpus Christi, near where Harvey came ashore on Friday as the most powerful hurricane to hit Texas in more than 50 years. The president will later go to the Texas capital Austin to meet state officials, receive briefings and tour the emergency operation center, the White House said.

Forecasters could only draw on a few comparisons to the storm, recalling Hurricane Katrina, which devastated New Orleans and killed 1,800 people in 2005.

The Weather Channel tweet

The administration of then-President George W. Bush faced accusations that his response was slow and inadequate - criticism that dealt a serious blow to his presidency.

Flood damage in Texas from Hurricane Harvey may equal that from Katrina, one of the costliest natural disaster in U.S. history, an insurance research group said on Sunday.

In Texas, thousands of National Guard troops, police officers, rescue workers and civilians raced in helicopters, boats and high-water trucks to rescue the thousands stranded in the flooding, which turned streets into rivers and caused chest-high water build-ups in scores of neighborhoods.

In Cypress, Texas, Kayla Harvey, 26, was monitoring Facebook, finding where people were stuck and organizing friends with boats to go out and help. "This is just what we do for our community. We don't wait for someone to come and help we just go out and do it," she said.

The last Category 4 hurricane to make landfall in Texas since Harvey was Carla in 1961. It packed winds and rains that destroyed about 1,900 homes and nearly 1,000 businesses, the National Weather Service said.