The mysterious recluse and heir to a copper fortune, Huguette Clark, died at age 104 on Tuesday morning in a New York City hospital.

After decades of living in obscurity, Clark captured media attention last year when MSNBC reported on her immense wealth, her three unoccupied residences valued at upwards of $220 million, and the criminal investigation over the handling of her finances.

A hospital resident by choice since the late 1980s, in her last years, Clark spoke only to private nurses and her accountant, Irving Kamsler, who is a convicted felon. Her attorney, Wallace "Wally" Bock, solicited a $1.5 million gift from Clark for his daughter's West Bank settlement.

Both Kamsler and Bock are under criminal investigation. No charges have been filed.

Clark inherited part of an immense 19th century mining fortune from her father, the reviled copper baron and U.S. Sen. William Andrews Clark of Montana (1839-1925).

With her sister, Andree, Huguette Clark grew up in a 121-room Beaux-Arts mansion at Fifth Avenue and 77th Street (now demolished) full of French Impressionist paintings, and works by the likes of Rembrandt, Donatello, Corot, Rodin, van Dyck, and Rubens, collected by her father. (His collection went to DC's Corcoran Gallery of Art.)

She divorced in the 1930s and had no children.

Among the properties Clark left behind, and their mysterious contents, is a 42-room Fifth Avenue apartment and a prime oceanfront estate in Santa Barbara which is reportedly furnished with paintings on the walls. Clark last visited the California property in the 1960s.

Besides reports of a private sale of a Stradivarius violin for $6 million and an auction of a Renoir painting for $23.5 million, Clark's possessions have been kept under wraps.

Her empty New Canaan, Connecticut, estate is on the market for $23 million.