September 11, 2001 is a day we will never forget. The United States and the world watched in horror as terrorists attacks resulted in the loss of almost 3,000 people after al-Qaeda terrorists hijacked four passenger planes to be flown into buildings in suicide attacks. Two of those planes, American Airlines Flight 11 and United Airlines Flight 175, were crashed into the North and South towers, respectively, of the World Trade Center complex in New York City. Within two hours, both towers collapsed with debris and the resulting fires caused partial or complete collapse of all other buildings in the complex.

A third plane, American Airlines Flight 77, was crashed into the Pentagon, leading to a partial collapse in its western side. The fourth plane, United Airlines Flight 93, was targeted at Washington, D.C., but crashed into a field near Shanksville, Pennsylvania, after its passengers tried to overcome the hijackers. Almost 3,000 people died in the attacks, including the 227 civilians and 19 hijackers aboard the four planes. It also was the deadliest incident for firefighters and for law enforcement officers in the history of the United States, with 343 and 72 killed, respectively.

We would like to remember this day with a sense of patriotism, our heads up high and our chest out with pride that this nation was able to overcome the deadly attacks, and that its ongoing war against terrorism has stopped many other terrible acts that would harm the country, its citizens and the morale of its people. Here are seven quotes to remember 9/11.

“You can be sure that the American spirit will prevail over this tragedy.” –Colin Powell

“When people endure a traumatic event, they are either defeated or made stronger. On Sept. 11, I told New Yorkers, 'I want you to emerge stronger from this.' My words were partially a hope and partially an observation that people in New York City handle big things better than little things. I could not be more proud of the way my city responded.” –Rudy Giuliani

“Freedom itself was attacked this morning by a faceless coward and freedom will be defended... We will not tire, we will not falter, and we will not fail.” –George W. Bush

“This mass terrorism is the new evil in our world today. It is perpetrated by fanatics who are utterly indifferent to the sanctity of human life, and we the democracies of this world are going to have to come together and fight it together.” –Tony Blair

“Time is passing. Yet, for the United States of America, there will be no forgetting September the 11th. We will remember every rescuer who died in honor. We will remember every family that lives in grief. We will remember the fire and ash, the last phone calls, the funerals of the children.” –George W. Bush

“The attacks of September 11th were intended to break our spirit. Instead we have emerged stronger and more unified. We feel renewed devotion to the principles of political, economic, and religious freedom, the rule of law and respect for human life. We are more determined than ever to live our lives in freedom.” –Rudy Giuliani

“Even the smallest act of service, the simplest act of kindness, is a way to honor those we lost, a way to reclaim that spirit of unity that followed 9/11.” –Barack Obama