The United States continues to mourn the loss of the 2,977 lives lost during the 9/11 terrorist attack. This year marks the 19th anniversary of the coordinated attack on the World Trade Center and the Pentagon.

The attack resulted in over 25,000 injuries and is the deadliest terrorist attack in human history, as well as the deadliest incident for firefighters and law enforcement officers in U.S. history.

The four passenger airlines departing from the Northeastern United States set flight for California was captured by 19 al-Qaida terrorists. Two of the hijacked planes crashed into the north and south twin towers in Manhattan.

The first crash instantly killed hundreds of people while trapping hundreds more in the burning 110-story north tower. No more than 20 minutes after the first attack, another plane plummeted into the south tower.

Millions viewed New York for the first time come to a stop.

An hour later a third plane crashed into the headquarters of the U.S. Department of Defense in the Pentagon in Arlington County, Virginia, leading to the partial collapse of the west side of the building. Over 100 military personnel and civilians were killed along with all 64 passengers aboard the flight.

The fourth hijacked plane was initially supposed to be flown into Washington D.C. but was thwarted by passengers, crashing into a field in Stonycreek Township, Pennsylvania.

The twin towers were built from steel in a tubular structural system, differing greatly from any other building of its time, according to a civil and environmental engineering professor at MIT .

It was this unique engine that was brought to the ground by a 200 mph Boeing 767 airline, painting the bright morning sky with a massive louring cloud of smoke and dust. President George W. Bush sat in front of a class of elementary students as he received word that “America is under attack.”

As American leaders faced a threat one could have never imagined, first responders and citizens became heroes as they attempted to rescue people from flames and cancerous fumes. Many inside the towers were suffocated by the fumes, and 10,000 people were diagnosed with 9/11-related cancer by 2018, according to History.com.

Amid a pandemic, recession and the demand to dismantle systemic racism, the country continues to commemorate those lives that were lost during this tragic disaster.

“Nineteen years ago, on this day, at this hour, on this field, 40 brave men and women triumphed over terror and gave their lives in defense of our nation,” President Donald Trump said during brief remarks in Shanksville, Pennsylvania on Friday. “Today, we pay tribute to their sacrifice – and we mourn deeply for the nearly 3,000 precious and beautiful souls who were taken from us on September 11, 2001.”