New York City lost an important philanthropist Thursday morning in an apparent suicide . Arthur Zankel, 73, a former Citigroup board member and vice chairman of Carnegie Hall, jumped from a ninth-floor stairwell window into an inner courtyard of his Fifth Ave. apartment building. He was discovered later that day and taken to New York-Presbyterian. He had not left a note.

Zankel, a trustee at Columbia University’s Teachers College and Skidmore College, had a mind for investment and a passion for philanthropy. Most notably his gift of $10 million to Carnegie Hall helped spearhead construction of the $100 million, 600-seat venue that bears his name. Zankel Hall, completed in 2003, fulfilled Andrew Carnegie's original vision of having three performance spaces of varying sizes in one complex (the other two are the 268-seat Sanford I. Weill Recital Hall and the 2,804-seat Isaac Stern Auditorium).

Zankel leaves behind a wife and four sons from a previous marriage. A memorial service is scheduled for 11:30 a.m. Sunday at the Frank E. Campbell Funeral Chapel on Madison Ave.