More than 20 Alexandria residents, many of whom had already paid January's $450 rent, were forced to leave their Old Town apartments yesterday after public safety officials condemned their building as a roach-infested firetrap.

Arturo Laso, a busboy at Henry Africa, an Old Town restaurant one block from the condemned building at 711 King St., was one of those ordered to pack his family's belongings and find a new home.

"It's such an injustice," Laso, 34, a native of Honduras, said in Spanish. "I just paid my rent. Now I have to borrow a truck to move my things to one place and I'm going to stay at another."

Like all of the ousted residents, Laso does not speak English and paid the $400 to $450 rent because he could not find a less expensive apartment near the restaurant or his wife's housekeeping job.

City officials have warned that skyrocketing housing costs are driving the city's lower-paid work force to the outer counties. Yesterday housing officials, aware that affordable housing is scarce and that as many as 91 percent of the city's landlords restrict or prohibit children, said that the six families affected by the condemnation lived in the "inhuman" and unsafe conditions because they felt they had no choice.

"It's deplorable," said Shirley Davis, the city tenant relocator. "It's inhuman for them to have to live like that."

In the five second-story apartments roaches scurried across ceilings, cracked plaster exposed pipes and uncovered electrical wires sprang from walls.

"We're afraid someone will get burned or killed," said public safety inspector Rodney Claytor. "We don't want to put them out, but the filth and the infiltration of roaches makes it unsafe."

Claytor said the landlord, K.S. Park, was warned of the violations in November but did not bring the building up to code. Park could not be reached for comment.

Magda Gotts, spokeswoman for the Alexandria United Tenant Organization, said that the families' plight demonstrates the need for a proposed city ordinance that would outlaw housing discrimination against children.

City Council member Patricia S. Ticer said she believed that "there is a general consensus" to begin forcing owners of some 17,000 city apartments where children are banned or restricted to ease the regulations.

"These people only had three days' notice," said Gotts. "How can they find a place in the city where housing is for the rich and families aren't allowed?"

While Laso said he would move in temporarily with relatives, others said they would have to go to the city's emergency shelter, where they can stay only five days because of heavy demand. After that, the tenants said, they did not know where they would go.

As those returning from late lunches stepped over the mattresses, chairs and laundry baskets parked on the sidewalk outside the condemned apartments, many peered into the building's wide-open door and gasped at the filthy, sagging stairs leading up to the apartments.

Said one woman: "I can't believe they allow such a thing."