They wander dusty roads searching hospitals and morgues for relatives who disappeared in the flood. Or they sit, staring into the distance from makeshift tents or from the doorsteps of the charitable who have given them shelter.

They are the more than 50,000 lost people of Armero and other towns ravaged by last week's monstrous, volcano-triggered mud flows. Without homes, without families, without jobs, they live an existence as empty as the now barren neighborhoods they were forced to flee.

Colombian authorities have held out the hope of new houses, prefabricated ones that could be put up quickly, probably not in Armero, where the extent of damage and death makes reconstruction impracticable, but possibly here in Guayabal, the closest town north of the destroyed town. There has also been talk in the press of a special economic aid package earmarked for survivors, but nothing definite has come of that yet.

For the moment, life for those fortunate enough to have escaped a disaster that killed 25,000 people is an arduous, often lonely, affair.

The primary objective of many is to locate other family members who may have survived a flood that tore parents from children and from each other in a night of horror.

Government and volunteer agencies have prepared long lists of the dead and injured. The lists are being collated by a Red Cross computer in Bogota, but many of the victims have not been identified and so are posted merely as "N. N.," meaning "No Name."

As a result, some of those looking for relatives travel from town to town in central Colombia personally checking rescue centers.

Henry Gomez Nieto, for instance, a 30-year-old coffee grower from Armero, was here today asking about his sister Mirian, a bacteriologist, who vanished in the flood. He had checked the lists in Bogota and had stopped at the hospital in Mariquita up the road. Having found no trace of her , he was on his way back to Armero, about four miles to the south, to pick his way through the ruins of their home, if he could find the spot in the tons of mud covering the town.

First aid workers here were offering tetanus and typhoid vaccinations to guard against the spread of epidemics feared from the 22,000 bodies decomposing in Armero. Two cases of typhoid have been reported. Gomez was standing in line to receive the shots. He said that if he failed to find his sister in Armero, he would move on to hospitals and cemeteries in Honda, Ibague, wherever disaster victims have been taken, until the mystery is solved.

"I'm not in any hurry," he said with resolve.

Another Armero survivor, a construction worker named Guillermo Rodriguez, was also on an odyssey searching for his 55-year-old father and 20-year-old brother. Was he worried he might not even be able to recognize the bodies should he come across them in Armero?

"Any way I find them I will take them," he said, appearing tired from his trek of the past six days. He said he had not slept much since the tragedy, listening for possible word of his family. The Colombian media have carried pictures and names of many of the injured to help link up relatives.

"How can I sleep if I have to listen every hour to the radio for the names being read?" said Rodriguez.

Sitting in a nearby doorway along one of Guayabal's narrow, cracked alleys was a 48-year-old woman whose scratched legs testified to her own tortuous escape from the catastrophe.

Her name is Bertilda Ireno, and she, too, is missing part of her family. She is convinced that two of her four teen-age daughters made it out alive, although why she believes this was not clear. She survived the mud flow by holding onto the top of a door frame.

While talking to visitors this afternoon, she suddenly thought she spotted her two daughters down the street. Two girls, one in a pink dress, the other in a blue one, were walking a block or two away. Moments later, when Ireno snapped out of her illusion and realized the girls were not her daughters, she broke into tears.

"All I'm doing is weeping about my solitude because I'm left alone," said the seamstress, whose sewing machines were washed away in Armero. "I've been through one big tragedy, and I'm just going to sit here waiting for the next one."

That the waters of the Magdalena River valley could flood again, if the volcano Nevado del Ruiz erupts again, remains a prevalent fear. The National Emergency Committee has been publishing daily status reports on the volcano, and the last few have downplayed the chance of any new menacing volcanic activity. But people are scared nonetheless.

Relief workers yesterday delivered powdered milk and sardines to the site, a welcome break from the rice soup and bread on which people there had subsisted.

In Armero the search for survivors continued today, with some workers using sophisticated sonar devices to locate trapped and mud-covered survivors. The national radio network RCN reported that five survivors were rescued.

To combat a serious looting problem, military authorities warned that pillagers might be shot on sight. "The Armed Forces will maintain order and tranquility," declared Army Gen. Manuel Guerrero Paz.