Social workers who deal with the District's abused and neglected children testified yesterday that difficult working conditions and staggering caseloads jeopardize the lives of the children they are supposed to care for.

"It's devastating to go home at night and not know if one of your kids is going to be on the 6 o'clock news because they died," said Thomas C. Wells, a social worker whose caseload consists of teenagers in foster care who have never found adoptive homes. "It's a lot of pressure."

Wells and other employees of the city's Child and Family Services Division told a federal court about how five of them share a car -- one that routinely is out for repairs for months at a time -- to make home visits. Wells, who doesn't own a car, gets to court hearings on a bike.

"There are times when I don't think I have any morale," testified another worker, Chainie Scott, who monitors children who have been subjects of abuse and neglect reports.

Scott spoke of how she juggled a caseload of 251 children while trying to answer the telephone in an office filled with crying children waiting to find places to sleep that night.

The two social workers spoke of their colleagues with admiration, and voiced their frustration at working in an agency where, they said, no matter how often city officials promise change, nothing ever seems to change for the better.

It was the first time that social workers have been heard from in a week-old trial of a lawsuit filed by the American Civil Liberties Union against the District. The suit alleges that the city is violating the rights of the roughly 2,200 children in its charge by failing to reunite them with their families or put them up for adoption.

Agency officials have refused to comment on the case, but have said in the past that chronic budget problems caused the understaffing.

The agency's budgetary problems are a reflection of the city's budget crisis. According to court records on file in the case, about 80 of the agency's 240 social worker positions are now vacant.

At the same time, the District's drug crisis has exacerbated the problems social workers have to deal with, increasing the number of children abandoned by parents addicted to crack and increasing the number of children who are consigned to grow up in crack houses.

Scott said agency policy calls for her to write a case plan for every child under her care within 45 days of the first report the division receives on them, and a new case plan every six months thereafter.

In reality, she said, she and her colleagues routinely fall months or years behind those deadlines because of the necessity of dealing with daily crises and massive caseloads. When that happens, she said, her children are at risk of languishing in foster care or living with abuse and neglect.

"When there are at least 251 children on my caseload, it is impossible to visit my clients . . . let alone their families," Scott testified. At other times, she said, she refers clients to other city agencies or firms that contract with the city to provide services such as drug or mental health counseling -- and finds later that services aren't available.

Wells said that neither he nor his colleagues ever received training on the computer system that is supposed to keep track of the thousands of children in District custody. The only user's manual in his office, he said, is one he wrote in his spare time.

Wells also testified that he and about 50 of his colleagues made a major effort in August 1988 to alert then-Mayor Marion Barry to the problems in their office. They were granted a meeting, where, according to Wells, the mayor promised to immediately hire 32 additional caseworkers -- filling half of the agency's existing vacancies -- and to get them new cars and set up a task force to monitor problems.

The task force met, according to Wells, but as of three months later the caseworkers still had no new cars and only one new caseworker had been hired unit. Meanwhile, Wells said, seven others had quit. Eventually, he said, the agency did get some new cars, but there still aren't enough to go around.

"Those are the reasons why people leave -- it's demoralizing," he said.

While the afternoon's testimony focused on insiders' views of the agency, the morning's testimony vividly described the human cost of its failures.

A woman who adopted a 3-year-old boy three years ago described the effects of the child's having spent 2 1/2 years in a series of foster homes. The child's biological mother abandoned him when he was 7 months old.

Both the mother's name and the child's were stricken from the court record by U.S. District Judge Thomas F. Hogan to protect their privacy. The mother, who gave her name only as Susan, is a 39-year-old District employee.

So fierce was her son's fear of abandonment, Susan said, that for a time he played a game with her whenever they took walks: He would stop at the corner and let her walk ahead almost to the end of the block.

"Then he would scream, 'Mama, don't leave me!' and run to catch up," she said, struggling to hold back tears.

After his first foster parents began having marital problems, she said, her son was put into another foster home, where he was abused -- something she did not learn for a year because his vocabulary was so limited that he did not know how to describe to her what had happened.

"He had no concept of reading a book," she said. "He couldn't turn the pages. He'd been put to sleep every night with the television by his foster mother. He didn't know any animals. He'd been told that everything with four legs was a dog."

Once, she said, she gave him a helium balloon, which he accidentally let slip one day from his grasp. The balloon, she said, seemed to symbolize his sense of how the world worked.

"For months after that," she said, "I'd have to assure him that he wouldn't float up in into space like that balloon." As she spoke, several courtroom observers wept.