The towers of the World Trade Center collapsed on September 11, 2001, as a result of the Twin Towers being struck by jet airliners hijacked by terrorists affiliated with al-Qaeda during the September 11 attacks. Two of the four hijacked airliners crashed into the Twin Towers, one into the North Tower (1 World Trade Center) and the other into the South Tower (2 World Trade Center). The collapse of the twin towers destroyed the rest of the complex, and debris from the collapsing towers severely damaged or destroyed more than a dozen other adjacent and nearby structures. The South Tower collapsed at 9:59 am, less than an hour after being hit by the hijacked airliner, and at 10:28 am the North Tower collapsed. Later that day, 7 World Trade Center collapsed at 5:21 pm from fires that had started when the North Tower collapsed. As a result of the attacks to the towers, a total of 2,763 people died. Of the people who died at ground level and in the towers, 2,192 were civilians, 71 were law enforcement officers, and 343 were firefighters. Aboard the two airplanes, 147 civilians and 10 hijackers also died.