Report, hundreds were killed instantly by the impact while the remainder of the fatalities were from the people trapped by the damage done to the tower. Evidence suggests that approximately 800 people survived the initial crash but were left stranded. The various causes of death ranged from smoke inhalation, immolation, jumping or falling from the upper floors, or the skyscraper's eventual collapse. Although a few people would subsequently be found alive in the rubble following the collapse of the towers, none of these individuals were from above the impact zone. 24 people were still officially listed as missing in 2006 and as of September 2021, the remains of 1,106 victims of the attacks have yet to be identified. John P. O'Neill was a former assistant director of the FBI who assisted in the capture of 1993 World Trade Center bomber Ramzi Yousef and was the head of security at the World Trade Center when he was killed trying to rescue people from the North Tower. Neil David Levin was the executive director of the Port Authority of New York and New Jersey, which was the governmental entity that built and owned the World Trade Center complex. He was eating breakfast in the Windows on the World restaurant at the time of the attack on the North Tower. Cantor Fitzgerald L.P., an investment bank on the 101st–105th floors of One World Trade Center, lost 658 employees, considerably more than any other employer, and also lost 46 contractors and visitors. Marsh Inc., located immediately below Cantor Fitzgerald on floors 93–100 (the location of Flight 11's impact), lost 295 employees and 63 consultants. Risk Waters, a business organization, was holding a conference in Windows on the World at the time, with 81 people in attendance.Field, Peter, Remembering September 11 The Day I'll Never Forget , Risk Waters website Carr Futures, located at the 92nd floor immediately below the point of impact, lost all 69 employees that were in the office that day. The plane did not hit the 92nd floor but the stairwells leading down were rendered impassble by debris and the elevator shafts were severed, making escape impossible. Everyone in the 91st floor survived and escaped. South Tower As with the North Tower, the exact number of those killed at or above the floors of impact in the South Tower has never been verified for definite, although it is estimated that around