Unfortunately, these are still preliminary figures: President Juan Manuel Santos

Devastating mudslides in the Colombian town of Mocoa killed at least 254 people, 43 of them children, President Juan Manuel Santos said.

Mr. Santos, who travelled to the reemote southern town to personally oversee relief operations, warned that the death toll could keep climbing.

“Unfortunately, these are still preliminary figures,” he wrote on Twitter. “We offer our prayers for all of them. We send our condolences and the entire country’s sympathies to their families.”

This handout photo released by the Colombia Presidential Press Office, shows an aerial view of a portion of Mocoa, Colombia on April 1, 2017, after an avalanche of water from an overflowing river swept through the city as people were sleeping. In this handout released by the Colombian National Army, soldiers carry a victim on a stretcher, in Mocoa on Saturday. President Juan Manuel Santos declared Mocoa a disaster area and said that at least 207 were killed but that the death toll was changing "every moment." Rescuers walk in the river with chainsaws after flooding and mudslides caused by the heavy rains in Mocoa on Sunday. Authorities said another 200 people, many of them children, were injured and just as many were unaccounted for. A man walks among the ruins after the havoc caused by flooding and mudslides. Mocoa is vulnerable to flooding. It is surrounded by the three rivers in a natural basin created by the surrounding mountains. A soldier stands guard next to a damaged home in Mocoa on April 2, 2017. The crisis is likely to be remembered as one of the worst natural disasters in recent Colombian history, though the Andean nation has experienced even more destructive environmental catastrophes. Firefighters search for survivors in Mocoa on Sunday. According to the Red Cross, 202 people were injured and 220 believed missing. People walk over the debris of a collapsed building in Mocoa on Sunday. Survivors described gruesome scenes in the remote southern town, as rescuers kept up a bleak search for victims in the muck and debris. Rescuers look for bodies in a river in Mocoa. The risk of a disaster has grown worse in recent years because of deforestation, which eliminates some protection from runoff, and many people had built their homes close to the water. People wait to identify bodies of their relatives in a cemetery, in Mocoa on Sunday. While dozens stood at the door of a hospital, hoping for good news of family members who were not on the list of those confirmed dead or injured, others frantically knocked on relatives’ doors, hoping to find someone with information about their loved ones. A man washes a shirt in muddy water in Mocoa, on Sunday. Health authorities said they had dispatched sanitation specialists in hopes of preventing epidemic outbreaks. A backhoe removes debris and mud from a street in Mocoa. Colombian officials pledged aid to rebuild homes, and the Attorney-General launched an investigation into whether local and national authorities responded adequately to the disaster.

Mr. Santos declared an emergency to speed up aid operations.

“The rain fell on Mocoa with an intensity and force that was without precedent and devastating,” Mr. Santos said. “It rained in two hours what falls in a month in Bogota.”

Mr. Santos said they would launch a health and vaccination campaign in the city to prevent an outbreak of diseases.

“Mocoa needs to rise up from this blow,” he said. “And it will.”

Gruesome scenes

Survivors described gruesome scenes, as rescuers kept up a bleak search for victims in the muck and debris.

Covered in mud, 38-year-old Marta Gomez told of going to search for her missing niece — and making a chilling find instead.

“I went to look for my niece, but I couldn’t find her. I dug and dug and found what turned out to be a baby’s hand. It was horrible,” she said in a shelter set up for the newly homeless.

As she stood in line waiting to register for government assistance for those who lost their houses, she told AFP she had given up on finding her niece.

“The mud took her away. I’ll never see her again,” she said, clinging to the leash of her equally muddy German shepherd.

Rescuers on it

Rescuers worked in stifling heat under a cloudy sky in the remote Amazon town, the capital of Putumayo department.

The debris left by the mudslides was everywhere: buried cars, uprooted trees, children’s toys and stray shoes sticking up out of the mud.

The torrent of mud, boulders and debris struck the town with little warning late on Friday after days of heavy rains that caused three area rivers to flood. It swept away homes, bridges, vehicles and trees, leaving piles of wrecked timber.

Most of those hit are poor

Most of the hardest-hit neighbourhoods in the town of 40,000 are poor and populated with people uprooted during Colombia’s five-decade-long civil war.

A “profoundly saddened” Pope Francis said he was praying for the victims.

Health authorities said they had dispatched sanitation specialists in hopes of preventing outbreaks of disease.

An unexpected offer of help also came from the Revolutionary Armed Forces of Colombia (FARC), a leftist rebel group engaged in a historic peace process with the government. It said FARC members were prepared to help rebuild the town.

Marta Ceballos, a 44-year-old street vendor, said she lost everything, but is thankful her family is alive.

Toddler grandson washed away

Jose Albeiro Vargas last saw his grandson the night a fierce rain came and unleashed havoc on this small city surrounded by rivers and mountains in southern Colombia.

From what the store owner has been able to gather, the torrents of mud, water and debris unleashed on the city of Mocoa by the rain-swollen river swept away his 18-month-old grandson, Jadir Estiven. On Sunday, Vargas was searching for the boy and the infant’s young mother, his daughter. The baby’s father survived.

“They were hit by the strongest avalanche,” said Mr. Vargas, the owner of a clothing store who was so tired from the search effort that he could barely open his eyes or speak.

What all could be salvaged

Maria Cordoba, a 52-year-old resident, said two of her nephews, aged 6 and 11, were killed when their house was destroyed. “The mother as well was totally beaten up” but managed to save her 18-month-old baby, she said as she used the river to try to clean items she salvaged from her home.

The death toll from the flood, one of the worst natural disasters to strike the country in years, was expected to rise as many people were injured or remained unaccounted for, and bodies were still being pulled from the thick mud, tree limbs and debris that covered much of the city. The deluge smashed houses, tore trees out by the roots and washed cars and trucks away.

Search-and-rescue teams combed through the debris and helped people who had been clawing at huge mounds of mud by hand. Many had little of their former lives left to search through.

Floors, only traces of houses

“People went to their houses and found nothing but the floor,” said Gilma Diaz, a 42-year-old woman from another town who came to search for a cousin.

Dozens stood in the door of a hospital, hoping for news of family members who were not on the list of those confirmed dead or injured. Others frantically knocked on relatives’ doors, hoping to find someone with information about their loved ones.

A rescue worker in an orange jumpsuit emerged from one search area with the body of an infant wrapped in a towel. Not far away, Abelardo Solarte, a 48-year-old resident of Mocoa, held a child’s shoe as he helped clear debris.

“You have no idea how many kids there are around here,” Mr. Solarte said.

A father’s grief

Jair Echarri, who came from a nearby town to help, also struggled to comprehend the loss of so many children. “I feel an enormous sadness because it’s filled with kids’ things, toys, clothes, school books,” he said. “I am a father and this breaks my heart.”

Mocoa is vulnerable to flooding. It is surrounded by the three rivers in a natural basin created by the surrounding mountains.

The danger has grown worse in recent years because of deforestation, which eliminates some protection from runoff, and because many people built their homes close to the water. But the triggering event was rainfall of more than 5 inches (130 millimeters) that began late Friday.

A 1989 hydrology report for the Agricultural Ministry warned that just such a disaster could happen unless steps were taken to reinforce the riverbanks, channel water away from the town and restore some of the forest. It was not immediately clear why those steps had not been taken.

Heard it and was saved

Juan Chanchi de Ruiz, 74, said the noise of the surging flood woke her up and gave her enough time to get to higher ground. Her house was unscathed, but several neighbours’ homes were heavily damaged and many people fled with some of their belongings.

“Around here, there’s nobody. Everybody left,” she said.

Colombian officials pledged aid to rebuild homes, and the attorney general launched an investigation into whether local and national authorities responded adequately to the disaster.