Cantor Fitzgerald's corporate headquarters and New York City office, on the 101st to the 105th floors of One World Trade Center in Lower Manhattan (2 to 6 floors above the impact zone of a hijacked airliner), were destroyed during the September 11, 2001 attacks. At 8:46:46 a.m., six seconds after the tower was struck by the plane, a Goldman Sachs server issued an alert saying that its trading system had gone offline because it was unable to connect with the server. Since all stairwells leading past the impact zone were destroyed by the initial crash or blocked with smoke, fire, or debris, every employee who reported for work that morning was killed in the attacks; 658 of its 960 New York employees were killed, or 68.5% of its total workforce, which was considerably more than any of the other World Trade Center tenants, the Police Department, the Port Authority Police Department, the Fire Department, or the Department of Defense. CEO Howard Lutnick himself was not present because he was taking his son to his first day of kindergarten, but his younger brother, Gary, was among those killed. Lutnick vowed to keep the company alive, and the company was able to bring its trading markets back online within a week.