The floors hit during the 9/11 attacks on the World Trade Center were as follows:
- The North Tower (1 WTC) was struck by hijacked Flight 11 between floors 93 and 99 at 8:46 a.m.
- The South Tower (2 WTC) was hit by hijacked Flight 175 between floors 77 and 85 at 9:03 a.m.
The impacts caused devastating damage and fires on these floors, with the North Tower's impact zone being more centralized and higher than the South Tower's. The North Tower's stairwells and elevators were severed or blocked from the 50th floor upward, trapping many people above the impact zone.
The South Tower's impact was slightly lower and offset, leaving one stairwell intact, which allowed some people to escape from the impact floors.
