A flash flood killed at least 31 people as it swept through a northern Mexican city.
Enrique Martinez, governor of Coahuila state, said two of those killed in Piedras Negras were children. He called the flooding some of the worst in the history of the US-Mexico border region, saying "the magnitude of destruction is enormous".
Throughout the day, authorities said as many as 75 people had yet to be accounted for, but the governor said many of those originally reported missing had been located.
Martinez said authorities were still hunting for more than a dozen people, but that he couldn't confirm the exact number of missing.
Floodwaters had receded and rain eventually stopped, allowing President Vicente Fox to visit this border city of 200,000 150 miles south west of San Antonio, Texas.
Struggling to be heard over cheers, the president addressed several hundred people at the municipal gym, which authorities had turned into a makeshift shelter.
"We will help each and every one of you recover your homes, furniture, belongings, and everything else you've lost," Fox said.
Five neighbourhoods hit hardest by flood waters were in the dark today, without electricity, gas service and potable water. But some of the people whose homes were still standing could be allowed to return to their homes later, despite forecasts of possible additional showers, the governor said.
"We have to be calm," Martinez said. "Because, while the water washed away everything in minutes, it will take weeks or months to rebuild."
The floods left behind houses without roofs, toppled walls and fences, and fallen power poles. Battered and overturned cars were scattered throughout the streets, yards and patios of riverside neighbourhoods, and the city remained without power, water and electricity.
"We lost everything, but thank God we're alive," said Oscar Tapia, 67, who carried a bucket of clothing salvaged from his house on the banks of the Escondido River, which overflowed as the result of the intense rains.
Tapia and his three sisters waded to safety after their house filled waist-deep with water.
Before Fox arrived at the shelter, hundreds of people, including dozens of large families, lined up to receive blankets, bottled water, spaghetti, beans and bread.
"That river brought death with it," said Tomasa Magallanes, who sat outside the gym. "You could hear many screams. The current carried cars and furniture as if they were toys."
The Magallaneses were rescued after four hours spent on the rooftop of their house. Their truck was swept away by the current.
Magallanes' husband, Lazaro Carrillo, 49, helped recover the bodies of two elderly women neighbours who were killed by the floodwaters.
Heavy rains began on Sunday, forcing water levels to rise by 25 feet in the Escondido, which flows into the Rio Grande. The downpours intensified around midnight, causing the river to overflow and in a matter of 15 minutes dozens of houses in Villa de Fuente, a working-class neighbourhood of tin-roof shacks.
Fox declared a state of emergency in the area, releasing government funds to help the city clean up and deploring soldiers to the area.
The US Border Patrol sent two helicopters to help rescue officials locate survivors stranded on rooftops and clinging to tree branches. Mexican government-owned helicopters arrived later from the Coahuila state capital of Saltillo.