Question: Roberta Brooke Astor, was an American philanthropist, socialite, and writer who was the chairwoman of the Vincent Astor Foundation, and great-great grandson of America's first multi-millionaire John Jacob Astor, a German–American businessman, merchant, real estate mogul and investor who mainly made his fortune in fur trade and by investing in real estate in or around where??
Sentence (from "Real estate investing"): The primary cause of investment failure for real estate is that the investor goes into negative cash flow for a period of time that is not sustainable, often forcing them to resell the property at a loss or go into insolvency.
Relevant evidence: No