For six years, John O’Neill was the FBI’s leading expert on Al Queda. He warned of its reach. He warned of its threat to the U.S. – But to the people at the FBI headquarters, O’Neill was too much of a maverick, and they stopped listening to him. He left the FBI in the summer of 2001. On September 10th, 2001, he started his new job, with a company called Kroll Associates, as head of security at the World Trade Center. A day later, he was dead, a victim of the September 11th terrorist attacks. He died at the World Trade Center.
NYTIME ARTICLE: http://www.nytimes.com/2001/09/23/nyregion/john-o-neill-is-dead-at-49-trade-center-security-chief.html
John Patrick O’Neill (February 6, 1952 – September 11, 2001) was an American counter-terrorism expert, who worked as a special agent and eventually a Special Agent in Charge in the Federal Bureau of Investigation until late 2001. In 1995, O’Neill began to intensely study the roots of the 1993 World Trade Center bombing after he assisted in the capture of Ramzi Yousef, who was the leader of that plot.
He subsequently learned of al-Qaeda and Osama bin Laden, and investigated the 1996 Khobar Towers bombing in Saudi Arabia and the 2000 USS Cole bombing in Yemen. Partly due to personal friction he had within the FBI and federal government, O’Neill was pushed out of the Bureau in 2001. He became the head of security at the World Trade Center, where he died at age 49 in the September 11, 2001 attacks. In 2002, O’Neill was the subject of a Frontline documentary The Man Who Knew, and cast as the protagonist in the television miniseries The Path to 9/11 and the 2003 book, The Man Who Warned America.