A teenager confined at the District's Oak Hill juvenile detention center died last night after suffering head injuries during a fight with two other youths on the afternoon before Thanksgiving, according to city officials and family members.

Karl Grimes, 18, who had been serving a sentence at the facility in Laurel that he received when he was a juvenile, was taken to Prince George's Hospital Center about 1 p.m. Wednesday after losing consciousness for a short time. During the altercation, he hit his head on a wall or windowsill in a day room in a residential unit where the three youths lived, according to an initial investigation by the D.C. Department of Youth Rehabilitation Services, which runs the facility.

Agency Director Vincent Schiraldi said in an interview that Grimes was lucid for most of the time he was at the hospital and that on Friday morning his condition was improving. However, by that afternoon, he was slurring his speech and had difficulty breathing and then slipped into unconsciousness again, Schiraldi said.

Schiraldi said the department is making a formal inquiry into reports he received that two of the three corrections officers who were in the unit during the tussle left the scene, leaving just one of the officers to break it up.

There was confusion among officials at Youth Rehabilitation Services during the weekend about whether Grimes was dead.

Schiraldi said the hospital told his agency Saturday that the teenager had died at 4 p.m. that day. About four hours later, after Schiraldi cut short a holiday stay on Long Island, N.Y., to return to the District, the director called D.C. Police Chief Charles H. Ramsey to notify him of the news. But yesterday, District police told Schiraldi that Grimes had in fact been pronounced brain dead, and relatives said he was on life support.

About 6 p.m. yesterday, Grimes was taken off life support.

"We are in shock. No family should have to experience what we are going through," said his mother, Patricia Grimes. Another relative said Karl Grimes was sent to Oak Hill because of a parole violation stemming from a school fight.

D.C. police spokesman Joe Gentile said authorities are investigating who is responsible for Grimes's death.

D.C. Council member Adrian M. Fenty (D-Ward 4), chairman of the Committee on Human Services, said the District must have a higher standard when it comes to ensuring the safety of youth who are in the government's custody.

"There should be enough supervision of these young people that they get separated before something tragic like this happens," Fenty said. "I'm going to demand accountability here. Who was on duty, how did they respond to the fight and what is management going to do about how this was handled?"

For many years, the 800-acre Oak Hill complex has been plagued by complaints of bad management, poor living conditions and drug activities, among other problems. Mayor Anthony A. Williams (D) and the D.C. Council agreed last year on a plan to close Oak Hill within four years and replace it with smaller facilities that meet national standards. The plan does not call for abandoning Oak Hill entirely; it calls for transforming the campus.

Schiraldi said confidentiality laws prevented him from discussing the nature of the fight, but he said the subject was "trivial." He explained that he did not call the police until Saturday evening because it didn't appear to be a serious incident with a serious outcome until then.

"There was not a big beef or a build up to the fight. It was a relatively sudden incident," he said. "It was not a brutal, premeditated kind of thing."

Schiraldi said the fight erupted soon after the youths had finished classes before Thanksgiving. The housing unit holds about 20 youths, many of whom might have witnessed the brawl.

Staff writer Cheryl W. Thompson contributed to this report.