''I saw something blue falling down,'' said Irene Lee, a nurse from Collingsworth, N.J., who was standing nearby and went to the victim as a cluster of bystanders gathered around him. ''I went up and took the seat off his head. I tried to take a pulse, but there was no pulse. People were running all over the place. It was pandemonium.''

Other witnesses in the Family Circle, the fifth and highest balcony in the opera house, said that they had seen the man earlier dangerously close to the edge of the railing.

''During the first intermission,'' said Hazel A. Rose, who was in the balcony near the victim, ''he was sitting on the railing, rocking back and forth. And then two ushers came by and pulled him away.''

About 10 minutes into the second of the 25-minute intermissions in the four-hour opera, the victim, who was clad in a dark blue pin-striped suit and wore a gold pocket watch on a chain, returned to the balcony railing, Ms. Rose said. He again climbed onto the railing and began rocking back and forth, she said, and when an unidentified male usher approached him, he plunged from the railing.

Many in the full-house audience of 3,800 had left the theater for the lobby and other areas, and the orchestra was less than half full during the intermission between the second and third acts of Giuseppe Verdi's opera, which was being broadcast to a nationwide radio audience over the Texaco Metropolitan Opera Network.