Tropical Storm Florence continued to thrash the Carolinas early Saturday with fierce winds, driving rain and catastrophic flooding. Downgraded from hurricane strength after making landfall, the storm had killed at least five people, the authorities said, and trapped hundreds of others whose rescues continued as night fell.

Among the dead were a mother and her infant child, who were killed after a tree fell on their house, the police said. The rains are anticipated to continue for days, and flooding is likely to worsen as more rivers spill over their banks.

Here are the latest developments:

• Florence made landfall around 7:15 a.m. Friday near Wilmington, N.C., as a Category 1 hurricane, with winds of about 90 miles an hour. By 2 a.m. Saturday, it had crossed into South Carolina about 25 miles west of Myrtle Beach, and the wind had dropped to 60 miles an hour. Track the storm’s location here.

• More than 360 people had been rescued in the coastal city of New Bern, N.C., by Friday evening, and another 140 were in need of help, a city spokeswoman said.

Gov. Roy Cooper of North Carolina said the worst might be yet to come and urged residents who had evacuated not to return home yet. He said forecasts predicted that the Cape Fear and Lumber rivers would rise “as high or even higher as in Hurricane Matthew,” which flooded similar parts of the state two years ago. “If the storm hasn’t reached you yet, it’s coming,” he said.

• Forecasters warned that the expected rainfall could reach up to 40 inches as the storm is expected to slowly move southwest into South Carolina before turning north.