SAN MARCOS, Texas - Relentless rain swelled the Blanco River 26 feet in an hour in central Texas, washing away hundreds of homes, and forcing the evacuation of at least 2,000 residents.
Officials in Hays County said at least 12 people are confirmed missing due to the flooding, which happened quickly and left entire neighborhoods with nothing but slabs.
The line of storms that is blamed for three confirmed deaths so far also shows no signs of letting up for some parts of the region.
Meanwhile, a tornado raged through a city on the U.S.-Mexico border, destroying homes, flinging cars like matchsticks and ripping an infant from its mother's arms. At least 10 people were killed, authorities said.
A Corpus Christi church says five of its parishioners are among eight people missing after a vacation home where several families were staying was swept away by a flash flood on the rain-swollen Blanco River.
Former Nueces County Commissioner Joe McComb says his 36-year-old son, Jonathan, is hospitalized in San Antonio with multiple injuries after the house was knocked off its foundation and carried down the raging river Sunday. It struck a bridge and then began breaking up.
Jonathan McComb's wife and their two children are among the missing, reports CBS affiliate KEYE-TV in Austin.
The Episcopal Church of the Good Shepherd says five members of two families from the Corpus Christi church also were in the house and are missing.
Four others inside also managed to escape.
Joe McComb told CBS affiliate KHOU-TV in Houston he was on vacation in Hawaii for his 44th wedding anniversary when he got the news.
McComb said he was told his son's family was staying at the river house with other couples in the Wimberley area when a wall of water took the home off it's foundation. McComb said at some point the families were all together but then hit possibly a bridge or embankment and were all separated.
Three deaths were blamed on the storms Saturday and Sunday, including two in Oklahoma and one in Texas, where a man's body was recovered from a flooded area along the Blanco River.
The weather system was expected to linger over a large swath of the region Monday, putting a damper on some Memorial Day plans.
Among the worst-affected communities were Wimberley and San Marcos, which are in Central Texas along the Blanco River in the increasingly popular corridor between Austin and San Antonio.
"It looks pretty bad out there," Hays County emergency management coordinator Kharley Smith said of Wimberley, where an estimated 350 to 400 homes were destroyed and where three people remained missing late Sunday. "We do have whole streets with maybe one or two houses left on them and the rest are just slabs."
"It sounded like a highway last night with water, refrigerators, equipment, everything rushing by," CBS affiliate KHOU-TV in Houston quotes one Wimberley resident as saying.