The floors hit during the 9/11 attacks were:

• North Tower (1 WTC): American Airlines Flight 11 crashed into floors 93 to 99 at 8:46 a.m.

• South Tower (2 WTC): United Airlines Flight 175 struck floors 77 to 85 at 9:03 a.m.

The impacts caused massive damage and fires on these floors, leading to the eventual collapse of both towers.