New York City took the brunt of the death toll when the Twin Towers of the World Trade Center complex in Lower Manhattan were attacked, with an estimated 1,600 victims from the North Tower and around a thousand from the South Tower.

On September 11, 2001, the loss of life at the World Trade Center was catastrophic. According to the official records, approximately 1,402 people died in or around the North Tower (1 WTC), which was the first building struck and the second to collapse. This higher death toll was largely due to the fact that the plane hit between floors 93 and 99, severing all three emergency stairwells and trapping everyone on the floors above the impact zone. In the South Tower (2 WTC), approximately 614 people lost their lives. Although the South Tower was the second to be hit, it collapsed first; the lower death toll compared to the North Tower is attributed to the fact that many people began evacuating as soon as they saw the first tower burning, despite initial "stay in place" announcements. These figures do not include the 157 passengers and crew on the two hijacked aircraft, the 343 firefighters, or the 71 law enforcement officers who perished during the rescue efforts. In total, 2,753 death certificates were issued relating to the attacks at the World Trade Center site.