Sam Zell, billionaire Chicago real estate magnate, dies at 81

May 18 (UPI) -- Sam Zell, a Chicago real estate magnate who became a billionaire by scooping up old properties, died on Thursday at 81.

According to Marketwatch, Zell popularized the real-estate investment trust and was known sometimes as a "grave dancer" because of his penchant for acquiring distressed real estate. He also founded Equity Residential, a real estate investment trust company.

"Mr. Zell was an iconic figure in real estate and throughout the corporate world," Equity Residential said in a statement. "An active investor in real estate since the 1960s, he helped revolutionize the industry through the popularization of the real estate investment trust ("REIT") structure in the 1990s, democratizing the ownership of publicly traded real estate companies.

Zell sold Equity Office to Blackstone Group for $39 billion in 2007.

However, he also controversially purchased the Chicago Tribune newspaper chain in 2007. The next year the publisher filed for Chapter 11 bankruptcy and Zell then left the company in 2010.

Zell is survived by his wife, Helen; his sister Julie Baskes and her husband, Roger Baskes; his sister Leah Zell; his three children, Kellie Zell and son-in-law Scott Peppet, Matthew Zell, and JoAnn Zell; and his nine grandchildren.