Yesterday morning, hours after a group of rowdy youths smashed display windows and looted his Southeast Washington store, owner Mortimer Lebowitz opened up again for business just one hour late.

For Lebowitz, owner of the Morton's Department Store chain in Washington, it was almost business as usual. Two of his stores were looted and burned during the 1968 riots, all have been subject to frequent break-ins and robberies, and earlier this year another of his stores was forced to close after it was damaged in another fire

"The first thing I thought when I hear about it was, 'Here we go again," said Lebowitz, who has proudly refused to move his stores from the heart of impoverished Washington despite repeated problems.

"I guess you could say I am frustrated," he said. But I'm not bitter."

His store was damaged in a rampage Monday night after police and youths clashed at a concert at Anacostia Park. According to police, angry youths, without any apparent motive, began smashing windows at Morton's at 2324 Pennsylvania Ave. SE and at an adjacent liquor store.

Police said Morton's, which sustained about $75,000 damages, most of which is covered by insurance, was hit for no apparent reason other than it was in the path of the crowd of about 400 youths.

But Monday night's incident did create a sense of deja vu for Lebowitz, who was one of many victims in the riots of 1968 following the assassination of the Rev. Martin Luther King Jr.

Despite the devastation of the riots, when many businesses that were looted or destroyed closed up completely and left the city, and despite years of facing higher District taxes and employment wages compared to what he would have to pay in other jurisdictions, Lebowitz has remained. He says he is committed to making a success of his low-markup, cash-and-carry business and to the concept of serving low- to middle-income communities.

"I have to tell myself that it'snot directed against me," Lebowitz said. "I have got to understand the social history that causes these problems and, thirdly, I have to strive for the solutions to those problems."

Now gray-haired and sporting a white goatee, Lebowitz, 67, born on the east side of New York, has remained for more than three decades an activist working to open up employment opportunities for blacks in the city.

During the late 1950s and early '60s, he served as president of the Washington Urban League, championing black causes and pushing for employment opportunities. He carried his liberalism further than simply his pocketbook, marching with King in Montgomery, Ala., and becoming one of the first, if not the first, store owners in the city to integrate dressing rooms. He also was one of the first to hire blacks as clerks and managers.

Before that time, blacks, largely held to menial jobs in stores, could buy goods at city department stores, but could not try them on.

"He and his wife Adele contributed to causes, but they did more than that, they put their shoulders to the grindstone and worked to influence other white business leaders to hire blacks in other positions," said Flaxie Pinkett, an influential black businesswoman and Lebowitz's longtime friend. "He helped to broaden the membership of the Urban League to include whites and he set the example for others to follow."

As he fidgeted with silverware at lunch yesterday, occasionally drawing diagrams on paper place mats to illustrate his points, Lebowitz outlined a philosophy that bases advances for minorities on job opportunities and education.

"Twenty years ago I thought that jobs and education over a couple of generations would take care of the problems in society," he said. "I am not so sure anymore."

"This whole thing is not a race problem anymore but a problem of an undisciplined, disoriented society," he said. "This morning I heard about [Fort Hunt High] school opening after it had been burned by white kids. The problems exist not in any certain community, but all over."

He rejects the notion that the looting of the 1960s and Monday night's looting were the result of anti-Semitic or antiwhite feelings in the black community. He believes, after years of working with blacks, that he understands it enough to know the lootings were not acts of vengeance.

"I could not live with myself if I ignored what I learned years ago in college in a course called Race Relations 3B," Lebowitz said. "Just coming out of the depression and sensitive to the fact that I was Jewish and a member of a minority, I became extremely sensitive to race relations.

"When I moved to Washington in 1935 at the age of 23 to start my own business, I very early discovered that black people in town were being ill treated," he said. "We found that by treating blacks fairly, we found their gratitude and they started coming [to the stores] in great numbers."

"We stocked merchandise that catered to the low- to middle-income people, and initially most of our customers were white," Lebowitz said. When he integrated his dressing rooms, whites started leaving as blacks flocked to his stores.

"It was a whole new experience for black people then to share the same fitting rooms as whites and to be treated as well," he said. "We tried to keep the white trade, but we never made concessions and we have never suffered for it."

"I have worked hard for causes all my life since Sociology 3B, and to sit down now and say 'hell with it' would be to say that none of my life since then has been worth it. I would have lost more than my business. My friends and the experiences of most of my adult life."