Torrential rain -- up to 20 inches in spots -- pummels much of Texas

Much of Texas was deluged Saturday by pounding, relentless rains -- up to 20 inches, in some locales -- causing dangerous flooding that washed away cars, a train and, possibly, one person.

And there's the possibility of more rain, with the remnants of Hurricane Patricia expected to roll across the state.

A 41-year-old homeless man was missing in San Antonio. He went after his dog near a drainage ditch "and he got swept away" about 4 a.m., fire department spokesman Christian Bove said.

Authorities called off the search a few hours later with no sign of the man, though the dog he'd been chasing was found safe. Bove said a full-scale search will resume when water levels recede.

Rain was letting up in the city by late afternoon after a morning of heavy rain. San Antonio broke a daily rainfall record by 10 a.m., according to the National Weather Service.

Forecasters had warned rain could fall at a rate of 4 inches per hour and swell parts of the San Antonio River around Interstate 410.

A similar story -- of rain, rain and more rain -- played out across many other parts of Texas.

The emergency office in Navarro County, about 250 miles northeast of San Antonio, noted several reports of a jaw-dropping 20-plus inches of rain Friday into Saturday.

A Union Pacific train with dozens of cars carrying cement derailed in Corsicana, one of Navarro County's hardest-hit communities, though not before two workers on it managed to stop it, climb out, then swim to high ground, company spokesman Jeff DeGraff told CNN.

"They are in good condition, no injuries, just a little wet and shaken up," DeGraff said.

The rain in this vicinity caused intermittent closures of Interstate 45 between Dallas and Houston -- the latest coming around noon, near Corsicana -- not to mention corresponding miles-long traffic jams.

First-responders launched several rescue missions to help people stranded in their vehicles, some of which video showed were all but undetectable under floodwater.

In Fort Worth, Jane Dysart had to be rescued when her car stopped running through water in the street, reported CNN affiliate KTVT.

"The SUVs and all were going through it and the trucks," she said. "I didn't."

In the central Texas town of Temple, authorities rescued a man from a tree, CNN affiliate KWTX reported. He climbed it when he lost control of his car and had to escape the rising water, KWTX said.

News Courtesy: www.cnn.com