Residents and rescuers resumed the desperate search for survivors Sunday in the Colombian city of Mocoa, one day after surging rivers drove a wall of water and debris through the city, killing at least 207 people and injuring 200 more.

Scores of people remained missing amid the vast sea of mud, debris and destruction, Colombia President Juan Manuel Santos said. He said he would help lead the effort to restore water service and power to the devastated area.

The tragedy was triggered by a deluge that dumped 5 inches of rain on the region Friday night, about half the amount of rain the region normally gets for the entire month of March, Santos said. Early Saturday, the Mocoa River and its tributaries overwhelmed their banks. Santos blamed climate change for the disaster.

"These rains are increasingly more intense, so we have to be ready," Santos said, according to the Associated Press.

Warning the death toll could rise as the search for survivors continues, Santos declared a state of emergency for Mocoa, a small city of about 40,000 located near the southern border with Ecuador.

Carlos Iván Márquez Pérez, director of the National Disaster Risk Management Unit, said more than 1,300 soldiers, police and emergency officials using helicopters, planes, boats and all-terrain vehicles "will work without stopping" on rescue efforts Sunday.

Street vendor Marta Ceballos told the Agence France-Presse she survived but is haunted by the memory.

"To see how some people screamed, and others cried, ran, tried to flee in cars, on motorcycles, and how they were trapped in the mud. It's all too, too difficult," she said.

Pope Francis, speaking in the Italian town of Carpi, said he was "profoundly saddened" by the tragedy and was praying for the victims and those grieving the loss of their loved ones.

The torrential rains triggered what the Colombian army called an "avalanche" of muddy and debris-strewn water from the Mocoa River and its tributaries. City streets soon filled with rushing water that crushed homes, pulled up trees from their roots and whisked away cars and trucks.

Witnesses said buildings vibrated as the muddy waters swiftly swept through the unsuspecting city. Many residents didn't have time to scramble to rooftops or to escape to higher ground. Mocoa Mayor Jose Antonio Castro said houses in 17 neighborhoods were wiped out.

Oscar Londono told the Associated Press he walked through mud-strewn streets to the neighborhood where his wife’s parents live. It was destroyed, but rescue workers sent him toward a nearby mountain, where he found his relatives camped with other survivors.

“To know they were alive,” he said, “it was a reunion of tears.”