September 11 Anniversary: 50 Pictures We’ll Never Forget

Today marks the 13th anniversary of the September 11, 2001, tragedy, when four coordinated terrorist attacks by the Islamist group al-Qaeda killed nearly 3,000 people in New York City and Washington, D.C.

Four passenger airliners were hijacked that day and flown into buildings as human missiles in suicide attacks. Two of these planes ended up crashing into the the World Trade Center complex of New York City, one was flown into the Pentagon, and a fourth whose target was Washington, D.C., was brought down in Pennsylvania by passengers who overcame the hijackers.

It's a solemn day in America as we remember the loved ones we lost and how one fateful day changed everything.

These photos are meant to be a reminder of the sacrifice made by everyday Americans for the price of our freedom, and what we must do to preserve it.

Above, the American flag over the White House flies at half staff as U.S. President George W. Bush addresses the Nation from the Oval Office after the deadliest terrorist attacks ever against the United States of America killed thousands. (TIM SLOAN/AFP/Getty Images)