Storm-battered Houston began limping towards recovery Thursday as Harvey's floodwaters started receding there, though the historic storm was still wreaking havoc further east.
While clouds parted at last in America's fourth-largest city, rural areas of Texas were drenched as Harvey headed eastwards, with the city of Port Arthur especially hard hit.
Authorities in Louisiana scrambled to safeguard their state from Harvey, whose onslaught evoked painful memories of Hurricane Katrina's deadly strike 12 years ago -- but New Orleans escaped with minimal rain.
Vice President Mike Pence was to visit Texas Thursday to meet victims of the torrential rains and assess damage.
Though some areas had finally caught a glimpse of blue sky, dangers remained for the US Gulf Coast, not least the threat of explosion at a chemical plant near Houston.
Also in Houston rescuers had recovered bodies of six family members from a van swept away by floods over the weekend.
"Our worst fears have been realized," Harris County Sheriff Ed Gonzalez told journalists, confirming the bodies of Manuel and Belia Saldivar and four of their great-grandchildren had been discovered.
Officials believe at least 33 people have been killed in the storm. There is little doubt the toll will rise further -- although many of those unaccounted for may simply have no phone or power access.
More than 30,000 people have found refuge in shelters across the Lone Star State, from the giant Houston convention center to small churches, according to the head of the Federal Emergency Management Agency (FEMA), Brock Long.
In Houston, where Mayor Sylvester Turner issued an nighttime curfew to aid search efforts and thwart potential looting, the two major airports reopened on a limited basis, signaling a slow return to normality.
Turner told journalists trash pickup and metro service will resume in some areas where flood waters have receded.
"It's my hope that despite how massive this storm has been, that the city of Houston will quickly move to get back to where we were and then beyond that," Turner said.
The National Hurricane Center downgraded Harvey to a tropical depression Wednesday night, but warned life-threatening flood conditions remain in southeast Texas and southwest Louisiana.
- 'City underwater' -
At least a quarter of Harris County, which includes Houston, is still under water -- and the operators of an organic peroxides plant outside the city warned they were bracing for the risk of an explosion after flooding caused them to lose all power.
"Right now, we have an unprecedented six feet of water at the plant," Rich Rowe, president and chief executive of plant operator Arkema Inc, said in a statement.
"We have lost critical refrigeration of the materials on site that could now explode and cause a subsequent intense fire," he said. "The high water and lack of power leave us with no way to prevent it."
Officials had already ordered the evacuation of an area within 1.5 miles (2.4 kilometers) of the plant in Crosby, northeast of Houston, and Rowe said the facility itself had been evacuated for employees' safety.
Even as Houston got a first glimpse of life-after-Harvey, the city of Port Arthur was pummeled by torrential rains -- making it almost impossible to reach despite the best efforts of volunteer rescuers.
Justin Coleman was part of a crew of jeeps and boats that drove overnight from Fort Worth trying to reach Port Arthur, but were forced to turn around on their first attempt.
"There's a lot of babies and elderly that are stuck in their homes right now. They said it's getting up to their chests," the 33-year-old told AFP during a gas station stop in the nearby town Winnie.
So far, parts of Texas have seen more than 50 inches (1.27 meters) of rain, while in Louisiana, the top total 18 inches so far was increasing.
- Dodged a bullet -
Harvey first slammed onshore as a Category Four hurricane Friday night before unloading on Texas.
As a tropical storm it then made its second landfall just west of the Louisiana town of Cameron early Wednesday, packing maximum sustained winds nearing 45 miles per hour.
Forecasters are predicting another five to 10 inches of rain in the region, with the downpour finally expected to stop on Thursday.
For now, southwestern Louisiana is taking the hardest hit, with a levee being breached in the town of Gueydan.
While New Orleans appeared to have dodged a bullet, the arrival of Harvey nevertheless served as a somber reminder, coming just one day after the 12-year anniversary of Katrina, which ravaged the vulnerable city famous for its jazz music and cuisine.
"I began to pray for the people in Texas after having gone through that same experience myself as a Katrina survivor," said Crystal Harris, who works for a bank taking donations for storm victims.
- 'Lessons learned' -
In Texas, the damage wrought is staggering -- Enki Research put its "best estimate" at between $48 billion and $75 billion.
At least one bridge had crumbled, one levee had breached and dams were at risk, while Harvey sparked the closure of several major refineries across what is a major hub of America's oil industry.
More than 4,500 people and 1,000 pets have been rescued from the storm zone by the Coast Guard, which expected to rescue an additional 1,000 people Wednesday in the Port Arthur area alone.
The Coast Guard has deployed about 50 aircraft and two dozen boats, but the overall rescue effort, involving other military branches and state police, easily tops more than 100 aircraft.
"We are certainly bringing lessons learned from Katrina," Admiral Paul Thomas, who oversees Coast Guard operations in 26 states, told reporters in New Orleans -- noting that several members of his team are Louisiana natives who are veterans of the 2005 disaster.