At last -- 4,801 days after the riot fires were finally under control on April 7, 1968 -- there is visible, tangible hope for the reconstruction of Northeast Washington's H Street corridor.

The hope is the official dedication next month of the first segment of Hechinger Mall.

Considering the mall's location and market, to say nothing of politics and torrents of noisy rhetoric, it is incomprehensible that the first convining evidence of reconstruction should have been more than 13 years in the making. Whole nations, after all, have risen from near-total ruin to powerful prosperity in an equivalent amount of time.

The fashion these days is to blame big-government bungling and praise big-business enterprise.

The fact is, however, that free enterprise failed us on the H Street riot corridor and that government came to the rescue. What that tells us about Reaganomics in the inner city is depressing.

The handsome, earth-red Hechinger Mall is located at one of the busiest gateways to the city, the intersections of Bladensburg and Benning roads and Maryland Avenue.

It commands a triangel of exceptional business opportunity, although at the western point of this triangle is riot-ravaged H Street, one of this city's worst pockets of desolation.

A generation ago, this stretch of H Street was one of Washington's finest shopping streets. Many of the boarded-up, deteriorating buildings, notably the Art Deco Atlas Theater, still bear witness to that. The decline began in the 1960s. The riots damaged or destroyed 90 buildings and about half of the street's stores. The scars are still much in evidence.

A seemingly endless succession of renewal plans, revitalization bureaucracies and verbose citizen-participation sessions seems only to have made matters worse. Crime, insurance rates and hostility seem to have increased. People have gotten into the habit of shopping downtown.

But north of the triangle and of Blandensburg Road, along the hills of the National Arboretum, are mostly the tree-shaded streets and blossoming front yards of Washington's black middle class. To the west, beyond Maryland Avenue, is increasingly gentrified Capitol Hill, teeming with affluent, young professionals.

The Capitol is only a mile away.Seen from the shopping mall and from Maryland Avenue, its dome is the focus of a magnificent view.

What all this adds up to, estimates John W. Hechinger Sr., the president of the lumberyard chain, is a market of 150,000 to 200,000 residents without much in the way of nearby services. The number does not include 100,000 commuter cars from the vast suburbia east of the mall, beyond the Anacostia River, which pass twice a day.

The 35-acre site was once a railroad yard. Sidney Hechinger, John's father, who started the business in 1911 at 6th and C streets SW, bought it 57 years ago for a lumberyard and distribution center. Ten years ago, after the riots, John decided to put the land to a higher use -- one that would be more productive both for him and the city. He was a city councilman at the time.

Some 20 different schemes were drawn up by a well-known architect. They included apartment buildings, offices and stores in various combinations deemed financially and socially most attractive. The architect was Robert McMillan of The Architects Collaborative in Boston, the firm of the famous Walter Gropius, which designed the original format of the Hechinger stores.

John Hechinger, meanwhile, was extending his lumber, hardware and home services empire beyond this metropolitan area, north into Philadelphia and south into Richmond and Tidewater. As home building declined, Harry Homeowner bought ever more tools and materials to repair and improve what he had.

But John Hechinger could not borrow the money to develop his property on Benning Road. It is considered "a high-risk area." It is being red-lined. b

"I went to all the big developers, the banks, the insurance companies -- investors as far away as California," said Hechinger. Nobody would risk investing even in the lucrative Hechinger enterprise close to a desolate ghetto.

That is, in the end, why all of the city's plans and rhetoric were frustrated. In January 1975, seven years after the riots, former mayor Walter Washington told investors "to stop shucking and jiving." It did not help.

The shucking and jiving went on until, two years ago, the federal Department of Housing and Urban Development came through with a $13.3 million "urban development action grant," supported by Connecticut Mutual Life Insurance Co. The UDAG program has since been severely cut.

The Hechinger Mall is the first of its kind in Washington and will surely be its most successful. Weeks before the official dedication on June 12, its Safeway was doing a landslide business, and there were long lines at Hechinger's checkout counter.

In addition to the 58,000-square-foot Safeway, the largest in the country, complete with health food counter, pharmacy and yogurt bar, and the 80,000-square-foot Hechinger's with the largest shopping carts I ever saw, there is a Peoples Drug Store and some 40 small stores on two levels.

Throughout, the enterprise shows an exceptional sense of good, no-nonsense design and merchandising.

The building was designed by RTKL, a big Baltimore firm that is a little more human than this gruesome accumulation of letters would indicate, with engineering help from Paul Salditt. With its all-around arcade and interesting two-level configuration, making clever use of a 30-foot drop in grade, it appears somehow more urban and appealing than most run-of-the-mill suburban shopping centers.

The graphics, by Chermayeff & Geismar, who are among America's best-known designers, state their business with refreshing, unpretentious clarity. The interiors of Hechinger's and Safeway are equally commendable for their bright simplicity.

Stores of this size often bewilder their customers and induce a kind of angst also experienced on fast-moving freeways. The idea is to push and frighten us into "impulse buying." Here the big stores display their wares in a straightforward manner.

Most impressive of all is that this shopping center shows no condescension. The customers are from different income groups and levels of education. But the merchandise, the displays, the sales appeal, show uniformly good taste -- even sophistication -- without distinctions. There are no gimmicks, screaming bargain-basement huckstering, phone come-ons. Customers are treated as responsible, discriminating adults. That is flattering.

"We decided to give our community something so classy that everyone will treat it with care," said Hechinger.

It is bound to pay off.

If all goes well, Hechinger hopes to start construction of the next phase of the mall, across Maryland Avenue, as early as this fall. The dilapidated Sears warehouses on the site are to be replaced by stores, offices and -- if the Reaganomics situations permits -- desperately needed housing.

The H Street corridor, at any rate, is no longer a high-risk area. The HUD community action grant will now unleash community action -- and private investors, no doubt, will soon beat a path through its rubble.