Parts of Texas have experienced more than a foot (30cm) of rain over the weekend as the remnants of Hurricane Patricia hit the southern US.
Flash floods were reported, with a freight train derailed after the rail tracks were washed away.
Patricia was the strongest storm ever recorded in the Americas but quickly lost power as it passed over mountainous Mexican terrain.
There, the damage done was less than feared with no reported deaths.
Authorities have expressed relief, but some homes were flooded and water and power were out along parts of the thinly populated Costa Alegre. A clean-up is in progress.
Patricia quickly weakened but combined with a separate storm system to bring heavy rain to Texas and other areas on the Gulf of Mexico – with some areas getting more than a month’s worth of rain.
In Houston, Mayor Annise Parker warned residents to stay away from roads after dark and beware of flash floods. Several motorists were reportedly stranded.
The US Grand Prix at the Circuit of the Americas near Austin was also affected by the bad weather.
In San Antonio, a man was reported to have been swept into a drainage ditch and is now considered missing, authorities said.
Flood warnings were in place for eight south-eastern Texas counties.
The town of Powell, 60 miles (100km) south of Dallas, worst hit, Reuters news agency reported, with 20in (50cm) of rain falling over the weekend.
Flooding derailed a freight train on Saturday near Corsicana. The two crew swam to safety
Flights have been cancelled at Dallas Fort Worth international airport.
However, meteorologists predict that the bad weather should clear during Sunday, moving on to Louisiana, Mississippi and Georgia, which could also experience heavy rain.