It was 11:05 on a balmy Monday night, June 25, 1906, the roof garden dinner theater at Madison Square Garden. The crowd was jovially watching a musical. Someone was singing, "I Could Love a Million Girls" . . .

And Harry Kendall Thaw, heir to a $40-million fortune, got up from his table, pulled a pistol from his dinner jacket stalked over to where the building's architect, Stanford White, was sitting.

And shot him three times in the head.

Shocked silence, then screams and shouts. The 35-year-old Thaw handed his gun to a fireman at the elevator and went quietly.

White, 52, was a familiar figure in New York society, architect to the Vanderbilts, man about town. In his 24th Street studio he kept a red velvet swing where his girl of the moment could exercise prettily. It was the swing that made Evelyn Nesbit famous.

She was 15 when she met White and became his mistress. She was 21 when the eccentric and jealous Thaw, her new husband, murdered White after she confessed that the architect had seduced her. (another time, she said White was the only man she ever loved.)

Evelyn Nesbit died at 82 in a Santa Monica nursing home, but the world would always remember her as The Girl in the Red Velvet Swing. There was even a movie by that name, and her story is told again in the forthcoming film of "Ragtime," with Brooke Shields playing the nymphet fatale.

A good choice, though perhaps Shields looks too intelligent to be exactly right. The face that history recognizes as Evelyn Nesbit is the face of a 16-year-old with lips rather naively painted into a bee-stung shape and swooning, soft, brown eyes. You can find her in a variety of poses at the Smithsonian Museum of American History's "Platinum Women" exhibit of platinum photographs by Rudolf Eickemeyr, Gertrude Kasebier and Clarence H. White.

Alongside those coolly formal pictures of Mrs. John Jacob Astor, Mrs. Harry Payne Whitney and other society women, Nesbit's portraits glow with sexuality. Eickemeyr, for whom she modeled in 1901, has her in Greek robes, in gypsy costume, in fin de siecle high fashion, and the voltage of her gaze in every one of them makes you wonder just what was going on there. o

Like a lot of romantic triangles, the story didn't have a very geometric ending. Thaw pleaded the unwritten law of husbandly honor, was acquitted but later declared insane and spent seven years in an asylum. He died in 1947.

Nesbit, who had testified for him at the trial, drifted through life as a dancer and singer. She married her dancing partner after Thaw divorced her, scandalized London when she introduced the turkey trot and the tango. She tried to make a comeback on Broadway, but it petered out in the backwaters of New Jersey. She attempted suicide a couple of times. She got $30,000 for the movie rights to her story and lived on that for a while, later taught ceramics. She used to say she wished she had been a sculptor.

The story is remembered for some good lines. Thaw, upon his return to New York years after the shooting, is supposed to have gaped at the new skyscrapers going up and groaned, "My God, I shot the wrong architect!"

But it was Nesbit who had the last word. "Stanny White was killed, but my fate was worse," she once murmured. "I lived."