Courtesy of Gregg Hansson
The morning of September 11, 2001, was sunny in New York City. Firefighter Gregg Hansson had just started his shift when a call came into his station. A plane had struck one of the Twin Towers. The two 110-floor skyscrapers were part of a huge office complex called the World Trade Center.
Hansson and five other firefighters hopped into their engine. They arrived on the scene in minutes. Thick black smoke was pouring from a huge hole high up in the building. At the time, people thought a small plane had accidentally hit it. But terrorists had hijacked, or taken over, a jumbo jet filled with passengers. They crashed it into the tower on purpose.
Panicked people ran from the building. But Hansson and hundreds of other first responders did the opposite.