资料题：Which floor was hit by the second jet（　）。

New York: When the first jet struck the first World Trade Center at 8:48 a.m.on Tuesday, the people in the second Word Trade Center with a view of the instant damage across the divide had the clearest sense of what they, too, must do: get out first.Katherine Ilachinski, who had been knocked off her chair by the blast of heat exploding from the neighboring tower, was one of those.Despite her 70 years of age, Ms llachinski, an architect working on the 91st floor of the second World Trade Center, the south tower, went for the stairs.Twelve floors above her, Judy Wen, an executive ( manager), screamed and set off,too.But others up and down the 110 floors, many without clear views of the damage across the way and thus unclear about what was happening, were not so sure.And the 18 minutes were ticking of before the next plane would hit.On this working day, the incident hit so many people into disorder.Amid the uncertainty about what was the best thing to do, formal announcements inside the south tower instructed people to stay put, assuring them that the building was sound and the threat was limited to the other tower.Some left, others stayed.Some began the climb down and, when met with more announcements and other cautions (警告) to stop or return, went back up.The decisions made in those instants proved to be of great importance, because many who chose to stay were doomed (注定死亡) when the second jet crashed into the south tower, killing many and stranding (使困在)many more in the floors above where the jet hit.One of those caught in indecision (优柔寡断) was the executive at Fuji Bank USA.Richard Jacobs of Fuji Bank left the 79th floor with the other office workers, but on the 48th floor they heard the announcement that the situation was under control.Several got in the lifts and went back up, two minutes or so before the plane crashed into their floor."I just don't know what happened to them,"Mr.Jacobs said.