Kenneth Ferguson, 25, had planned to keep cool Friday night by going to a friend's house to watch the 10 p.m. light heavyweight boxing championship on cable television. But when the fight at the D.C. Armory was canceled, Ferguson stayed home--and instead went for a late night swim at a city pool.

Several hours later, Ferguson was dead, the victim of an unexplained accident that occurred hours after closing time at the city-run public pool at the Kenilworth Parkside Community Center in Northeast Washington.

The dead man's family and the City Council member representing his district have raised questions about routine after-hours use and security provisions at city pools, which have traditionally been a magnet for youths in nearby neighborhoods during hot summer nights.

"If there had been someone from the city there, my brother would be alive today," Deborah Simms, Ferguson's sister, said yesterday.

City Council member H.R. Crawford (D-Ward 7), who chairs the council committee that supervises recreation and youth affairs, said yesterday he will call for an investigation of the Department of Recreation's procedures for supervising pools.

Crawford, whose ward includes the economically depressed Kenilworth neighborhood, said that unauthorized use of public pools is a common problem during summer months when young people seek to beat the heat after the customary closing time.

"In my ward, it is a common fact that people break into pools and we can't control it," Crawford said.

In this case, however, members of Ferguson's family said yesterday that Ferguson and his brother, Casey Ferguson Jr., 24, entered the pool with the permission of what they thought was a city employe.

"The pool was closed, but someone he thought was the lifeguard was letting certain people in," Casey Ferguson Jr. said in an interview.

The dead man's father, Casey Ferguson Sr., a construction worker who has lived in the Northeast neighborhood for more than 20 years, said yesterday he spoke with a city recreation official who he said told him that a pool guard had allowed youngsters in the pool after hours, then had left his post and put another man in charge.

City recreation officials could not be reached for comment yesterday.

Ferguson was fished from the pool at about 1 a.m. Saturday, given mouth-to-mouth resuscitation, and rushed to nearby Prince George's General Hospital, where he was pronounced dead, according to police and family members. Police said an autopsy is pending.

Casey Ferguson Jr., a file clerk at George Washington University, said he and his brother went to the pool, which is located at Anacostia Avenue and Ord Street NE, about 11 p.m. They were among a group of about seven or eight people who were swimming in the shallow end of the pool, playing tag and throwing a ball around, according to Casey Ferguson.

A brief fight erupted at the pool about midnight when young men from the neighborhood of the nearby Kelly Miller recreation center tried to scale the chain-link fence and enter the pool, Casey Ferguson Jr. said.

That group got into a shoving match with a group of Kenilworth residents who were outside the chain-link fence, Ferguson said. The young men in the pool were not directly involved in the fighting, but they were told to leave the pool by a man that Ferguson said he thought was a city lifeguard.

When the scuffle ended, he said, the swimmers spotted his brother, clad in red swim trunks, at the bottom of the deep end of the dimly lit pool.

After the fight, when the young men got back in the pool, Ferguson said, "I didn't see Kenny . . . I thought he must be in the locker room." Then someone spotted him beneath the water.

Kenneth Ferguson did not swim well, according to family members, and would not have attempted to swim alone in the deep end of the pool.

Kenneth Ferguson was a 1977 graduate of Spingarn High School, and had been a construction worker for several years, including a stint at Hercules Demolition Corp., where his father works. He had been laid off and recently landed a part-time job at a magazine and bookstand at the downtown National Press Club building.

Shortly before he drowned, his brother said, "He said he had to leave soon because he had to get up and go to work in the morning."

Ferguson lived with his family in the 4400 block of Quarles Street NE, and had grown up in the neighborhood.

"My mother and father are grieving real bad," said his sister, Deborah Simms, 27. "He was like the life of this family."

"He was a humorous guy," she said, "He would tease me and joke with me a lot. My mother said he was overprotective of her. He wanted to do things for her, like get her out of this environment and get her to somewhere better."