Within a matter of 15 seconds, towns were reduced to rubble. Buildings fell like dominoes, starting fires and sending up towers of smoke. A nation that had most recently been in the headlines for trying to end a 35-year- long guerrilla war was suddenly fighting to survive its biggest natural disaster since 23,000 residents of the town of Armero were buried by a volcanic mudslide in 1985.
As trapped people wailed from beneath the rubble, and their neighbours dug with their hands to try to free them, residents described the scenes after Monday's earthquake as like something out of Dante's Inferno. Some rescue workers spoke of more than 1,000 dead, and possibly twice that figure once the dust settles and all the buried bodies are reached.
The governor of one of theworst-hit states, Carlos Arturo Lopez, compared the scenes with the Second World War destruction of towns in Germany. "It looks like a city that has just been bombed to bits," he said after flying over one of the damaged cities, Pereira.
"Many bodies are lying uncollected in the streets. We don't have the men to pick them up," said Ciro Antonio Guiza, assistant fire chief of the city of Armenia, high in the Andes mountains.
The fire station, with a full day staff working at lunchtime on Monday, was one of the buildings to collapse.
With a population of 200,000, Armenia appears to have been the worst- hit city. Some 700 buildings are already reported destroyed in Armenia alone and about 180,000 people in the devastated region are thought to be homeless because of the quake. Many of the survivors of the quake, which registered six on the Richter scale, wandered Armenia aimlessly yesterday, trying to come to terms with both their terrible personal loss and the collective tragedy. The poorest barrios were the hardest hit.
Iliana Patricia Vega, 26, paced the working-class Brasilia Nueva district in tears, her bright red dress torn, her right shoulder naked. "Oh, my baby, he was so beautiful," she said of her 10- year-old son, Jon Alexander.
She was on the second floor with her son and six-year-old daughter when everything collapsed, killing the boy. "Does anyone have any medicine? Can I get some medicine?" she cried, fretting over a deep gash to the little girl's forehead.
While rescue teams worked with their hands, survivors preferred to gather round bonfires rather than return to the few homes not flattened by the quake or razed by the fires that followed. They have good reason to be afraid. Aftershocks are registering at 5.5 and 5.6.
Officials say it is still impossible to estimate how many died. But a toll of thousands appeared possible as bodies were pulled from buildings that had collapsed like stacked cards. Other rescue workers estimated that 60 per cent of buildings in Armenia had been destroyed in the poor southern suburbs, housing coffee bean pickers and other peasants.
Municipal sports stadiums in the city have become makeshift morgues, filled with bodies. At Armenia's Southern Hospital, where more than 350 people were treated yesterday, patients spent the night huddled on rusted trolleys. Doctors said at least 40 people had been pronounced dead at the infirmary.
Pedro Maria Londono, 46, and his family of four were saved when every room but the one they were in was destroyed. "In 12 seconds, I lost what took 20 years to build," Mr Londono said.
Five members of the professional football club Atletico Quindio - three Argentines and two Brazilians - were also feared dead in the ruins of a hotel. The quake even toppled the thick wall surrounding Armenia's San Bernardo prison, allowing some 80 inmates to escape.
Throughout the region, many of the buildings that collapsed were those rebuilt after the last serious earthquake, in February 1995, in which scores were killed.
In older times, the fertile Cauca Valley was renowned for some of the world's finest coffee beans. But over the past 20 years it also became a centre for a cartel growing coca leaf and refining it into cocaine. As in other areas of Colombia, Marxist guerrillas have moved in with protection rackets.
"We're overwhelmed by the magnitude of this earthquake," said Alberto Parra, head of the civil defence network. Though the confirmed tally of dead was 500 last night, and injuries 1,800, no one disputed that the final toll will be much higher. "We're finding more bodies every minute," said Quindio state's governor, Henry Gomez.
Colombia is to make an official plea to Britain for financial aid, the country's ambassador to London said last night.
Humberto De La Calle said discussions were under way between the Colombian authorities, the British embassy in Bogota and several British charities to decide how to organise the relief operation.