Rescuers continued plucking people from floodwaters across Texas on Thursday even as waters receded from Houston, revealing swathes of devastation wrought by Hurricane Harvey.
Donald Trump pledged to donate $1m in personal funds to the relief effort.
Emergency crews and volunteers in boats, trucks and aircraft scoured inundated suburbs around Houston and cities to the east for people still in need of evacuation.
Police rescued 18 people from floodwaters overnight, said Houston’s mayor, Sylvester Turner. “Crisis ebbing but far from over.”
In dryer areas recovery crews started to assess damage and remove debris. They braced for the discovery of bodies.
Harvey, once a category 4 hurricane, was downgraded to a tropical depression and moved over north-eastern Louisiana and into Mississippi.
Fires and two explosions early on Thursday at a chemical plant in Crosby, north-east of Houston, jolted residents to the presence of new dangers as waters recede.
The plant, which makes organic peroxides used in plastic resins and paint, lost refrigeration due to the storm. An executive warned that eight more tanks could burn and explode. Contradictory messages from officials left people unsure if emissions were toxic.
The Texas department of public safety said 48,700 homes sustained flood damage, including 17,000 with major damage and 1,000 that were destroyed.
The storm has killed at least 44 people in Texas, officials said on Thursday, and forced 32,000 people into shelters since it came ashore last Friday near Rockport on the Gulf of Mexico coast. It was the most powerful hurricane to hit Texas in half a century.
Officials ordered mandatory evacuation of some communities near the Barker and Addicks reservoirs, which continued to discharge water.
But much of Houston was dry and baked under a blazing sun.
The heat aggravated the stench from stagnant waters and flood-damaged properties. “Man, oh-ooh, that is foul,” said a shirtless man on Discovery Green, a park beside a convention centre which is sheltering 8,000 people.
The city’s health department urged residents to take precautions to minimise the risk of contamination and diseases such as cholera and typhoid.
“Practice good hygiene such as hand washing after any contact with #Harvey floodwaters,” it tweeted. “Do not eat any food that came in contact with #Harvey floodwaters. When in doubt, throw it out.”
Regular trash collection was due to resume on Thursday. Airports have resumed a limited service.
Despite the havoc of recent days, Houston remained calm. “No city curfew citations or arrests for a second night in a row. Thank you Houston for your understanding and cooperation,” tweeted the mayor.
Meanwhile, the White House announced on Thursday that Trump was pledging $1m in personal funds to the relief efforts.
The press secretary, Sarah Huckabee Sanders, called on the media to help decide which specific group or organisation he should give to. “He’d love some suggestions from the folks here and I’d be happy to take those if any of you have them,” she told reporters in the briefing room. “But as I said, he’ll pledge proudly a million dollars of his own personal money to help the people of both Texas and Louisiana.”
She said she was uncertain whether the donation would come from the president directly or his private foundation, which has been a source of controversy.
Trump and his wife, Melania, will travel back to Texas and to Louisiana on Saturday, Sanders added. The tentative plan includes the Houston area in Texas and possibly Lake Charles, Louisiana, but this may change depending on conditions. The president visited Corpus Christi and Austin on Tuesday.
Tom Bossert, White House homeland security adviser, estimated that about 100,000 homes would be affected by the floods. “That’s a big number. We’re going to have 100,000 affected homes, all with different degrees of insurance, some with flood insurance, some under-insured, some uninsured.”
The White House would soon send a supplemental spending request to Congress to help ease the recovery process, Bossert added, insisting that he was “not worried at all” about having sufficient funds for the current effort. “The disaster relief fund is strong, it’s got plenty of money in it now, and we’re going to ask for some very responsible surplus supplementals.”
Bossert claimed that “coordination is happening better than any storm we’ve seen before” and noted that 28 search and rescue teams and taskforces from 16 states had been sent to Texas. “In fact, I believe that that’s the first time we’ve activated all the taskforces since 9/11, so this is an all-hands-on-deck operation.”
The adviser said undocumented immigrants seeking government help should not be worried about their immigration status “unless they’ve committed a crime on top of coming here illegally”. No one would be denied help based on their legal status and shelters would not be subjected to inspections.
Asked about explosions at the Arkema chemical plant near Crosby, he said the situation was not a public health hazard in the sense that people around the facility had already been evacuated. “If they were there, it would be dangerous and they have to keep an eye on it and take it seriously, but for right now the people don’t seem to be there, so a tree falling in the woods, if you will.”
But further deaths in Texas are likely in the coming days, Bossert warned. “In the immediate response and recovery phase, people will use chainsaws, people will remove debris, people will be stressed ... so unfortunately, we will see additional losses of life, if history is any precedent here.”
