Deadly severe weather over the long holiday weekend tested government alert and evacuation procedures, as officials scrambled to deal with storms and historic flooding that left more than a dozen people dead and a similar number missing.
Crews will resume searches Wednesday for the 11 people who have now been missing for three days in the small tourist town of Wimberley, where the usually calm Blanco River swelled to an ocean-like squall that crested three times above flood stage. In Houston, where nearly a foot of rain submerged roads and stranded hundreds of motorists, Mayor Annise Parker said two people who capsized in a boat that was helping with rescue efforts Tuesday have not been found.
At least 17 people were killed in the Memorial Day weekend storms in Texas and Oklahoma.
By Tuesday evening, most Houston area rivers had receded back within their banks after a foot of rain was dumped on region — stranding hundreds of motorists and inundating the highway of the nation’s fourth-largest city.
The floodwaters affected virtually every part of the city and paralyzed some areas. Firefighters carried out more than 500 water rescues, most involving stranded motorists. At least 2,500 vehicles were abandoned by drivers seeking higher ground, officials said.
"Given the magnitude and how quickly it happened, in such a short period of time, I've never seen this before," said Rick Flanagan, Houston's emergency management coordinator.
Meanwhile, the search went on for at least 13 people who were still missing, including a group that disappeared after a vacation home was swept down the river and slammed into a bridge. In Hays County, about 35 miles southwest of Austin, Commissioner Will Conley said authorities were looking for at least 30 others who were missing.
The hunt for the missing picked up after a holiday weekend of terrible storms that dumped record rainfall on the Plains and Midwest, caused major flooding and spawned tornadoes in Oklahoma and Texas. More than 1,000 homes have been damaged or destroyed in Texas, and thousands of residents are displaced.
Authorities were also searching for victims and assessing damage just across the Texas-Mexico border in Ciudad Acuna, where a tornado Monday killed 13 people and left at least five unaccounted for.
Texas Gov. Greg Abbott declared disasters in 24 counties, and said he had deployed the state’s National Guard and was worried that the death toll could rise. President Barack Obama said Tuesday he had assured Abbott that he could count on help from the federal government as the state recovers from the flood.
"You cannot candy coat it. It's absolutely massive," Abbott said after touring the destruction.
The worst flooding damage was in Wimberley, where the vacation home was swept away leaving a dozen people missing. Wimberley is a popular tourist town along the Blanco River in the corridor between Austin and San Antonio.
Witnesses reported seeing the swollen river push the home off its foundation and smash it into a bridge. Only pieces of the home have been found, Hays County Judge Bert Cobb said.
Cobb had said Monday night that one person who was rescued from the home told workers that the other 12 inside were all connected to two families. Young children were among those believed to be missing.
Trey Hatt, a spokesman for the Hays County Emergency Operations Center, said Monday night that the "search component" of the mission was over, meaning no more survivors were expected to be found in the flood debris.
The Blanco crested above 40 feet — more than triple its flood stage of 13 feet. The river swamped Interstate 35 and forced parts of the busy north-south highway to close. Rescuers used pontoon boats and a helicopter to pull people out.
Hundreds of trees along the Blanco were uprooted or snapped, and they collected in piles of debris up to 20 feet high.
Flooding wreaked havoc late Monday afternoon in Austin, where emergency crews responded to more than 20 high-water rescues, and later in Houston, where the National Weather Service declared a flash flood emergency and an announcer at the Houston Rockets game asked fans not to leave because of severe weather.
Harris County Flood District, which includes Houston, advised residents not leave their homes early Tuesday after the weather service issued a flash flood warning for parts of the county. Before the sun rose Tuesday, emergency crews used helicopters and boats to help residents evacuate their flooded homes in Webberville, some 15 miles east of Austin.
The storm system also prompted reports of tornadoes across the state and was blamed for four deaths: a man whose body was pulled from the Blanco; a 14-year-old who was found with his dog in a storm drain; a high school senior who died Saturday after her car was caught in high water; and a man whose mobile home was destroyed by a reported tornado.
The Oklahoma Department of Emergency Management also reported four fatalities between Saturday and Monday across the state, which also saw severe flooding and reported tornadoes.
In Ciudad Acuna, Mayor Evaristo Perez Rivera said 300 people were treated at local hospitals after the twister, and up to 200 homes had been completely destroyed. The government was talking with families whose homes had been damaged to determine how much assistance would be needed to rebuild the city of 125,000 across from Del Rio, Texas.
"We have never registered in the more than 100 years in the history of this city a tornado," he said.
By midday, 13 people were confirmed dead — 10 adults and three infants. At least five people were unaccounted for. The twister hit a seven-block area, which Victor Zamora, interior secretary of the northern state of Coahuila, described as "devastated."
"There's nothing standing, not walls, not roofs," said Edgar Gonzalez, a spokesman for the city government, describing some of the destroyed homes in a 1-square mile stretch.
Mexican President Enrique Pena Nieto was expected to travel to Acuna with officials from government agencies.
Gonzalez said late Monday night that rescuers were looking for four members of a family who were believed missing, adding that there were still areas of rubble that remained to be searched. Zamora said rescuers were searching for an infant who was missing after the tornado ripped the baby carrier the child was in from its mother's hands.
Luis Antonio Hernandez, 37, looked in disbelief Monday at what remained of his house. Three vehicles had smashed through the back, leaving a heap of twisted metal and the smell of gasoline. Hernandez and his three children had hidden in a bathroom as the tornado sent the cars passing over them. "It's a miracle that we're alive," he said.
Residents retraced the tornado's path in trucks, hoping to salvage their mattresses, furniture and other belongings. But there was little left intact. Antonio Sanchez's home was now nothing more than an open shell strewn with rubble.
"We lost everything," he said. "But at least I didn't lose my family."