The rains from Tropical Storm Harvey pounded the Houston region on Monday, stranding thousands of residents — many on rooftops — awaiting rescue. Floodwaters are expected to continue rising for days.

Many turned to social media to get help: “My sister needs help!!!” read one tweet, followed by an address. Officials scrambled to reach stranded people, urging boat owners to pitch in on an enormous and frantic rescue. And with nearly two feet of rain still expected, the authorities worried the worst was yet to come. Here’s the latest:

• With record floodwaters, more than 450,000 people are likely to seek federal aid, the Federal Emergency Management Agency said on Monday. The agency has estimated that about 30,000 people will seek emergency shelter, and that federal aid will be needed for years. Read more on the storm here.

• Some 100,000 customers in the Houston area are without power, Floyd LeBlanc of CenterPoint Energy said. Repair crews have had trouble getting through the floodwaters.

• On Monday, local officials said the death toll had risen to 10 from five.

“In Harris County, we have six deaths that are potentially flood related,” said Tricia Bentley, a spokeswoman for the Harris County Institute of Forensic Sciences, which serves as both a medical examiner’s office and crime lab. Officials also reported one death each in Rockport and La Marque, and two in Montgomery County.

• More than 30 inches of rain has fallen on parts of the Houston area since Thursday, the National Weather Service reported, causing catastrophic flooding that officials have called the worst in the state’s history.

• The White House announced that President Trump and the first lady, Melania Trump, would be visiting Texas on Tuesday. They will arrive in Corpus Christi in the morning for a briefing on relief efforts, and then head to Austin for a tour of the Emergency Operations Center and a briefing with state leaders.

• Harvey turned back out to sea on Monday, with the center of the storm reaching the Gulf of Mexico south of Houston, the National Hurricane Center reported. It was expected to move to the northeast, along the Gulf coast toward far eastern Texas and southwest Louisiana.