Just after midnight on July 10, 1986, inmates at Lorton Reformatory set fires that sent spectacular flames shooting above the prison's rows of red brick dormitories. Four buildings at the Occoquan facilities were left in ruins, 14 other facilities damaged and 32 inmates and public safety officers injured. One inmate later died.

The incident focused new attention on an old but worsening problem: crowding in the city's prisons. Authorities say they determined subsequently that crowded conditions were not a direct cause of the uprising. But city corrections officials, prodded mostly by the courts, have made the elimination of crowding their top priority during the past year.

And despite the city's efforts, the crowding remains.

Corrections Director Hallem Williams Jr. said yesterday that the inmate population at Occoquan is larger than it was before the fires last July. But he argued that the department has attempted to alleviate the tension that may have contributed to the uprising at the prison complex, located in southern Fairfax County.

Since last July, the District has instituted more educational and recreational programs "to ensure less idleness" among inmates, and Lorton corrections officers have become increasingly vigilant, Williams said. He also maintained that inmates now better "understand the consequences" of destructive actions inside the prison.

"While it is still overcrowded, I don't think we have a volatile situation," said Williams. "I think we're on top of it. But there is still considerably more that needs to be done."

Several lawyers for Lorton inmates contend, however, that except for the emergency release of some prisoners this week, the District has still not taken significant steps to improve "tense and dangerous" conditions at Lorton.

"There has been a substantial deterioration since last year," said Ed Koren of the American Civil Liberties Union's National Prison Project, which represents Occoquan inmates. "Those places are real pits."

Most of the overcrowding is at Lorton's three medium-security Occoquan prisons, which house 1,970 inmates -- 689 more than the maximum number specified in a Dec. 22 order by U.S. District Judge June L. Green. Before last year's uprising, 1,626 inmates were housed in the Occoquan facilities.

On June 30, Green for the second time granted the city a one-month reprieve in meeting the court-ordered limit of 1,281 inmates at Occoquan.

But Green lashed out at city officials for not yet meeting the population ceilings. "Obviously, we are now at a crisis situation," Green said.

The D.C. Jail and four of Lorton's prisons -- Central, Maximum and the two youth centers -- are already under federal court-ordered population ceilings, and imposition of the Occoquan limits would leave only two institutions, Minimum and a 400-bed modular facility, without population limits. Each of these prisons now houses about 50 percent more than its rated capacity.

Mayor Marion Barry, under emergency powers granted by the D.C. Council, has allowed the early release of about 133 inmates this week from Lorton, the D.C. Jail and city halfway houses. Another 242 inmates have been made eligible for early parole, according to corrections officials.

District officials emphasized that clearing out prison cells was not the solution to the overcrowding crisis, but they said the city had to take action to meet the court-ordered prison population caps.

"We have done everything we can do," Barry said in a statement he released last week.

Under the emergency release process, Barry is allowed to reduce by 90 days the sentences of inmates convicted of nonviolent crimes, making them eligible for parole almost immediately. Barry is also permitted to reduce the sentences of some inmates serving maximum sentences by 90 days or 10 percent, whichever is less.

Inmates convicted of violent crimes -- including, for example, homicide, rape, assault with a dangerous weapon and armed robbery -- and those serving mandatory sentences on drug convictions will not qualify for early release.

Lawyers for the inmates in lawsuits against the District have urged the city to build "massive new facilities" to house the prison population, which is growing by about 200 people a month, largely because of the District's police crackdown on illegal drugs.

Koren, who recently visited the Occoquan dormitories, said that some inmates are double-bunked in a crowded room that is supposed to be a storage area.

"There was a power outage when we were there, and prisoners said that has happened a number of times," said Koren. "I don't know how they would get people out if there was an emergency. It's a dangerous situation. And there is no end in sight."

Williams said that the city is planning to break ground in the fall for an 800-bed correctional treatment facility near the D.C. Jail in Southeast Washington that is expected to be completed by 1989 or 1990. The District is also planning to increase its halfway house capacity and construct a 100-bed modular unit at Lorton's central prison to house temporarily inmates displaced by planned renovations at obsolete Lorton dormitories.

Fifteen persons, called leaders of last July's uprising by prosecutors, were indicted in April by a federal grand jury in Alexandria on charges that they plotted to burn Lorton's Occoquan facilities "to effect the early release of the prisoners." The 15 inmates, who were charged with participating in a riot and with conspiring to riot and commit arson, will go on trial Monday.

The indictment, alleged that the 15 met for more than a month to plan the disturbance, which caused $2.8 million in damage and forced the temporary relocation of 650 prisoners.

The uprising closely followed release of a consultant's report that warned of a volatile situation at Occoquan.