HOUSTON — Rescuers began a block-by-block search of tens of thousands of Houston homes Thursday, pounding on doors and shouting as they looked for anyone — alive or dead — who might have been left behind in Harvey’s fetid floodwaters, which have now heavily damaged more than 37,000 homes and destroyed nearly 7,000 statewide.

More than 200 firefighters, police officers and members of an urban search-and-rescue team fanned out across the Meyerland neighborhood for survivors or bodies. They yelled “fire department!” as they pounded with closed fists on doors, peered through windows and checked with neighbors. The streets were dry but heaped with soggy furniture, carpet and wood.

“We don’t think we’re going to find any humans, but we’re prepared if we do,” said District Chief James Pennington of the Houston Fire Department.

The confirmed death toll stood at 31, though it is expected to rise. But by midday, the temporary command center in a J.C. Penney parking lot had received no reports of more bodies from the searches, which are expected to take up to two weeks.

Unlike during Hurricane Katrina’s aftermath in New Orleans, crews used GPS devices to log the homes they checked rather than spray painting neon X’s on the homes, which also avoided alerting potential thieves to vacant homes.

Elsewhere, the loss of power at a chemical plant set off explosions that prompted a public health warning. The blasts at the Arkema Inc. plant northeast of Houston also ignited a 30- to 40-foot flame and sent up a plume of acrid smoke that the head of the Federal Emergency Management Agency initially described as “incredibly dangerous.”

FEMA later backed away from that statement, saying that Administrator Brock Long spoke out of an abundance of caution. An Environmental Protection Agency analysis of the smoke showed that it posed no immediate threat to public health, the agency said.

The French operator of the plant warned that up to eight more chemical containers could burn and explode as chemicals stored there degraded without refrigeration.

The latest statewide damage surveys revealed the staggering extent of the destruction. The figures from the Texas Department of Public Safety did not include the tens of thousands of homes with minor damage.

Rescues continued, as did the search for shelter among people made homeless by the storm. Emergency officials reported 32,000 people in shelters across Texas.

The Harris County FEMA director said the agency was looking at how to house people who have lost their homes to Harvey. The priority is to get them out of shelters and into some form of temporary housing, with hotels being one option, he said.

“Right now nothing is off the table,” Tom Fargione said Thursday. “This is a tremendous disaster in terms of size and scope. I want to get thinking beyond traditional methodologies you’ve seen in the past.”

As the water receded in the nation’s fourth-largest city, the threat of major damage from the storm shifted to a region near the Texas-Louisiana state line.

Beaumont, Texas, with a population of nearly 120,000, struggled with rising water. The city lost water service after its main pump station was overwhelmed by the swollen Neches River. That forced Baptist Beaumont Hospital to move patients to other facilities.