Remembering 9/11: The 17th anniversary of the deadliest act of domestic terrorism in American history

(CNN) -- On the 17th anniversary of the deadliest act of domestic terrorism in American history the heroic actions of those we lost reawakened us to the essential importance of personal courage.

Three-hundred and forty-one New York City firefighters. Twenty-three New York City police officers. Thirty-seven Port Authority police officers. Three court officers. Two EMS workers. Thousands of innocent civilians. Numbers alone, of course, cannot do them justice.

A whole portrait of America was taken from us in an instant: individuals of every race, religion, and ethnicity; fathers and mothers, children and newlyweds, brothers, sisters, and best friends.

Amid our grief it should not be forgotten that September 11 began as a beautiful blue-sky day. Primary elections were being held throughout the city, and as people were lining up to vote at polling places or dropping their children off at school, suddenly they stopped and turned their heads toward a rumble in the sky. It was 8:46 a.m.

The pilot of the first hijacked airplane, Mohammed Atta, was flying American Airlines Flight 11 low and loud down the length of Manhattan with the lives of 92 passengers in his hands, above stores, churches, and finally past the Washington Square Arch as he aimed for the heart of the Twin Towers.

At 9:03, the second plane banked sickly toward the south tower as the world watched on television. An orange blossom of flame exploded on our screens as a new reality dawned.

A stunned nation

On the streets people stood frozen in mid-commute, gathered at street corners, talking to strangers or on their cell phones, gazing at the blazing scars cut into the sides of the Twin Towers.

The steel seemed to have melted around the impact zone and it reflected the sunlight, giving the edges a quicksilver sheen, like an overwrought special effect. Despite the horror of the scene, there was an assumption that the worst had already occurred; few people thought that the towers would actually come down. After all, they had been bombed before in 1993, and though six people had died and thousands were injured, the Twin Towers still stood.

Subways were shut down and taxis proved impossible to find, so I made my way down Broadway against a sea of people evacuating uptown. Black smoke now filled the sky, evident from anywhere on the island. I expected to see mass panic, but instead the exodus was relatively calm and orderly. It was the response of a civil society to a massive attack.

Reporters announced to the world that people were throwing themselves from upper floors of the World Trade Center. One observer recalled them hitting the ground "like melons," as the music piped into the plaza played "How Deep Is Your Love?"

A man leaps to his death from a fire and smoke filled Tower One of the World Trade Center September 11, 2001 in New York City after terrorists crashed two hijacked passenger planes into the twin towers. (Photo by Jose Jimenez/Primera Hora/Getty Images)

Firefighters in full bunker gear were rushing up the stairs of the trade center as workers tried to get down to safety. This was the image that survivors would repeat over and over, "as we were going down, they were going up."

At 10:05, the south tower shuddered and collapsed; 23 minutes later the north tower fell as well. It was an avalanche in Lower Manhattan, reaching 2.4 on the Richter scale. The rumble of the buildings coming down was like a thousand jets taking off at once. Below the roar you could almost hear the collective sigh of human life, the disbelief, horror, and resignation as the steel finally buckled and 110 stories imploded, floor upon floor.

"A gray cloud of debris rolled violently across City Hall Park, an unforgiving wall of pulverized concrete against the still briefly blue sky. Then it hit City Hall, and everything became dark as night and quiet, except for the patter of debris hitting the roof of the old stone building. For a moment, we thought that we might all die, if not from the building collapse itself then from some biological agent swirling around in the air," John Avlon, who worked as Mayor Rudy Giuliani's speechwriter, recounts.

'Greater love have no man than this...'

On September 15, the first funeral was held. It was for Father Mychal Judge, the beloved Fire Department chaplain who had been killed by debris as he administered last rites to a fallen firefighter. There were more than 400 other heroes of the uniformed services and thousands of civilians from 83 nations. Their stories were told again and again in an attempt to assimilate the tragedy, to comprehend the incomprehensible.

There was the middle-aged woman from Kazakhstan who had reported early for her first day of work in America, and the young bond trader who was killed on her one-month wedding anniversary.

Firefighter John Chipura had survived the 1983 terrorist attacks on the Marine barracks in Beirut that killed 241 of his colleagues and then served seven years as a member of the NYPD before joining the Fire Department.

John O'Neil spent a career serving as a counterterrorism expert for the FBI and leading the search for Osama bin Laden after the al Qaeda attack on the USS Cole, before taking a job as director of security for the World Trade Center in August 2001.

Henry Thompson was a court officer who commandeered a van and raced to the towers with two of his co-workers.

Chief of the Department Pete Ganci had ordered his men to move the FDNY command post away from the trade center and then walked toward the burning buildings minutes before their collapse.

Glenn Winuk was a respected lawyer who also served as the commissioner of the volunteer fire department in his hometown of Jericho, New York; after the attack he helped evacuate co-workers from his law firm and then headed toward the towers to help the rescue effort.

Capt. Timothy Stackpole was a father of five who had recently returned to the job after recuperating from burns over 90% of his body that he suffered in a fire that killed two of his friends.

Police Officer Moira Smith had been among the first to report that a plane had smashed into the towers, and hours later this mother of a 2-year-old and wife of a police officer became the first female NYPD officer killed in the line of duty.

The legendary 71-year-old First Deputy Fire Commissioner Bill Feehan, who had held every position in the department, became the oldest New York City firefighter in history to die in the line of duty.

The dead are remembered

NEW YORK, NY - SEPTEMBER 11: Jose Morales, who lost his brother Martin on 9.1, and brought a replica of the twin towers to the North pool of the 9.11 (Photo by David Handschuh-Pool/Getty Images)

Firefighting and police work tend to be family traditions in the city of New York, and the attack affected some families and communities disproportionately: the brothers Joseph and John Vigiano; brothers Thomas and Peter Langone; brothers Timothy and Thomas Haskell; cousins Manuel and Dennis Mojica; and the father and son Joseph Angelini, Sr. and Joseph Angelini, Jr. — all died together on September 11. This was more than just the fraternal bond between firefighters and police officers; this was family.

Their services were held in small chapels, ornate synagogues, simple firehouses, and grand cathedrals. More than a dozen were held at St. Patrick's Cathedral on Fifth Avenue. It is there that you get the fullest sense of majesty and tragedy of this city transformed.

Rescue workers had been laboring at ground zero every hour since the disaster. At night the site was lit by spotlights, like a movie set. Fires had burned there for 80 days, rekindling when a lower level of the underground fire was exposed to the oxygen in the air.

Now tourists and well-wishers on pilgrimage sought out the site, standing at great distances, taking pictures of the hulking wreckage and skeletal spires looming over the fences. There were flowers left against every gate and poetry scribbled on paper taped to the lampposts. The missing-person posters that had appeared around the city in the days after the attacks now display heart-wrenching goodbyes and handwritten cards with photographs promising them that we would never forget.

NEW YORK, NY - SEPTEMBER 11: Flowers lay over names at the South Tower pool of the 9/11 Memorial & Museum. (Photo by Chris Pedota-Pool/Getty Images)

The largest mass grave in America existed uneasily as both hallowed ground and deconstruction site. The scope of the destruction, the size of the wound cut into the heart of our city, remained humbling and retrained its ability to inspire calm outrage, cold purposefulness.

Near the site, St. Paul's Chapel now serves as a shrine of sorts, its metal gates covered with posters and canvas tarps upon which people wrote notes urging faith, expressing sadness, and calling for courage. Inside, the chapel had been transformed into a sanctuary for rescue workers with beds, food, clothing, and massage tables, and occasionally a string quartet to help soothe their souls.

Along all the walls of the church, posted on pillars and taped in pews are letters and cards written by children from across the United States, covered with brightly colored drawings of eagles, firemen, the towers, gratitude: "Thank you... you were my heroes... I am sorry the people died.... Thank you for saving the people... I love the city... God Bless America."

These notes sustained the spirits of the men who each day would sift through the debris, finding body parts that, as often as not, would disintegrate at the touch. Their actions and those cards were powerful examples of why our city and nation would triumph over terror: In ways both large and small, we had met the worst of humanity with the best of humanity.

Undaunted

Our great symbol of world trade is now gone — what was intended by its architect to be a symbol of world peace was destroyed in a vicious, unprovoked act of war. But what was really attacked on September 11 was the idea of New York City and America itself — a beacon of freedom, diversity, and equal opportunity. That spirit is intact and undaunted. In fact, our devotion to those ideals has only been strengthened by the selfless heroism we have seen.

We now recognize that we are all part of a larger narrative, and while our city may never be the same, we will be better and stronger as a result of all we have experienced. Much has been taken from us, but much remains; and even in the dark, a great deal of light still shines upon New York City and these United States of America.