Everybody has a 9/11 story.Mine begins three days earlier, in an apple orchard outside Saratoga Springs, N.Y.One of my best friends from college was getting married. He lived in New York City and some of his buddies at the wedding worked at the World Trade Center. It was a glorious weekend of bluegr ass music and Calvados apple brandy. We flew home Sept. 10, 2001.Then the world stopped turning.On the morning of Sept. 11, I was driving down the Eisenhower Expressway, listening to the radio as I headed downtown to work.Network news reporters broke into the show from New York.The first plane had hit.Then the second.Stunned, I called my wife to tell her to turn on the TV as the Sears Tower loomed closer and closer in my windshield.Was Chicago next?Later, I called home to check on my family. I also reached my friend in New York.To my relief, his Wall Street buddies were safe.On Sept. 13, O’Hare Airport reopened and a flight was heading to White Plains, just outside New York City.My editors booked tickets for me, fellow reporter Bryan Smith and photographer Robert A. Davis. We raced through the airport and made the flight.The assignment seemed simple enough: Find the Chicago cops and firefighters who had dropped everything and rushed to New York to help — and follow them.But nothing about those days was simple. Firefighters make their way through the rubble after two planes crashed into the World Trade Center on Sept. 11, 2001. AP file I documented Chicago police officers searching a damaged office tower near Ground Zero, going floor to floor looking for the wounded or the dead.They found no one.What they did find was haunting: half-eaten bagels smeared with cream cheese, blue blazers hanging from the backs of chairs, desks abandoned in an instant.They were the remnants of an ordinary workday — and evidence of people who had run for their lives.I spent time at the camp where Chicago firefighters worked alongside New York’s first responders. They climbed onto the jagged, smoking mountain of rubble that had once been the World Trade Center.White dust, fine as talcum powder, swirled through the air. It coated people, vehicles, food — everything — in a ghostly film.When crews found the remains of fallen first responders on “The Pile,” the Chicago cops and firefighters trudged back to their camp, where the Chicago flag hung next to the Stars and Stripes on a wrought-iron fence.I can still see the tears cutting clean lines through the grime on the Chicago first responders’ faces.They left the New Yorkers to bring home their own.Twenty-five years later, that is what stays with me most: the courage, the camaraderie and the selflessness.Those Chicago cops and firefighters were truly serving and protecting. It was their highest calling.But I also remember the fear. The anger. The sorrow. The helplessness of watching terror unfold.Those feelings never entirely left me. They never entirely left America.They also shape the way I see innocent people elsewhere — in Ukraine, Gaza, Iran and other places where families look to the sky and wonder whether a missile is coming for their neighborhood.I think about the America that existed before 9/11 and the one that came after.Before the attacks, I was a cop reporter who could roam Chicago police headquarters at 11th and State streets, sometimes dropping unannounced into the offices of the police superintendent or the chief of detectives. Reporter Frank Main takes notes at a crime scene in July 2009.Sun-Times file After 9/11, the city built a fortress for the Police Department at 35th Street and Michigan Avenue.Nobody roams those halls like that anymore.Now we buzz into work with security IDs.We pull off our shoes and belts at airport checkpoints.We pass through metal detectors and x-ray machines at public buildings.And somewhere in the back of our minds is the thought we cannot quite shake: It could happen again.That, too, is part of the legacy of 9/11.So where were you when the world stopped turning? Related How did 9/11 change your life? Memories of 9/11 horror still fresh after a quarter-century Sept. 11-spawned surveillance is ravaging the country ...read more read less