It took about 15 seconds yesterday to do what a number of prominent New Yorkers and their supporters had been trying to achieve for 15 years.

Since 1963, the skeletons of two unfinished 15-story luxury high-rise apartment buildings loomed as eyesores and symbols of the controversy surrounding the development of Breezy Point, Brooklyn, as part of the Gateway National Park, the nation's first federal park in a city. The battle finally ended in spectacular fashion when long-time park supporters braved blustery weather to watch the two structures disappear in a cloud of high explosives and dust and then celebrated their demise with champagne.

"If destruction can be beautiful, that was," concluded Marion Heiskell, one of the leaders of the park effort, after the buildings were dynamited according to orders from the Natonal Park Service, which now runs this last undeveloped strip of beach in New York.

At issue since 1960 has been the ultimate character of Breezy Point. The two high-rise buildings, whose construction was begun in that year by the Atlantic Improvement Corp., were to be centerpieces of a planned luxury community of 50,000. The development frightened the group of tightly knit middle-class owners of modest summer cabins who had been coming to Breezy Point for years, and about 3,000 of them banded together to form their own cooperative. Against all odds, they came up with more than $11 million to buy from Atlantic Improvement the land under their houses, which they had been leasing.

At the same time, stiff pressure was mounting from Mar. Heiskell, wife of Time-Life board chairman Andrew Heiskell, Mrs. Marshall Field, and other well-known New Yorkers to preserve the three-mile beachfront area for recreational use by the public.

In 1963, Mayor Robert Wagner finally decided to acquire the point for a city park, and in the fall of that year the New York Board of Estimate took title to the land. To mmollify the summer residents, the city exempted their land from its plan. They continued to oppose the park, however, or any other change in the area which would bring an influx of people to the domain they once considered their own. The compromise that was reached was that they could keep their land, but the rest of Atlantic Improvement's went to the park.

President Nixon accepted the city's idea to create a federal park out of the peninsula on which Breezy Point lies in 1973, and the Gateway National Park formally came into existence in late 1973.

While some smaller skeletons of the same vintage as the high-rises blown up today are due to be demolished by more pedestrian methods soon, the most visible symbol of commercial threat to the area has ended with a bang. As soon as the city and the park service complete a final plan to provide the area with adequate facilities for expanded public use, federal legislation will be filed to appropriate money to finish the job.