Bruce Robert Isabell — he legally dropped Bruce as an adult — was born in Duluth, Minn., on June 2, 1952. His father, Joseph, was a lineman for the local power company. He worked in a flower shop as a boy, and after high school, moved first to Minneapolis, then to New York in the early to mid-1970s. For a time he worked for the party planner and florist Renny Reynolds, one of whose clients was Studio 54. Recognizing Mr. Isabell’s creativity, Mr. Schrager hired him to create parties on his own.