Sept. 11 has become one of those dates by which Americans measure time — before, and after. Although my family did not lose anyone in the attacks, our lives have changed profoundly.

My 13-year-old son, Kevin, and I witnessed the attacks from different vantage points in lower Manhattan. From a classroom in Intermediate School 89, a public middle school three blocks north of the World Trade Center, he watched United Airlines Flight 175 slam into the South Tower.

As Kevin fled his school, he saw people leap from the North Tower's upper floors. He had traveled only one block when the South Tower collapsed. For hours that day, he did not know whether I had survived; my office was across the street from the World Trade Center. When we finally were reunited and made our way home that evening, it was to a neighborhood reeling from loss.

The approximately 3,000 students who attended public schools in the neighborhoods surrounding the World Trade Center were immediately dubbed the "Ground Zero kids" by the press. Not only had they witnessed the attacks and massive loss of life up close, but they were displaced from their school buildings for months. The media speculated about the psychological damage they had sustained, whether they would ever recover, and whether it would be too traumatic to return them to their downtown school buildings.

As I struggled to recover from my own initial shock, I became increasingly worried about Kevin. I researched post-traumatic stress and learned that children who have witnessed acts of extreme violence regress to earlier ages. They cling to their parents, are overwhelmed by fears of another attack or of losing a parent, and become withdrawn from family and friends. They experience sleep disturbances, such as nightmares, and exhibit behavioral problems in school or at home. Kevin and his classmates had many of these symptoms.

Parents weren't faring much better. When I compared notes with friends, our symptoms were similar. We couldn't sleep. We had violent nightmares. We were unable to concentrate. We cried easily, often several times a day. We were haunted by the memories of what we had seen. Experts on trauma caution parents to shield children from their own fears. This has been difficult advice to follow in a city that has experienced two terrorist attacks in nine years, and is now consciously bracing itself for more in the future.

Still, as I read about strategies for helping children recover, I saw that my partner, Laura, and I had instinctively done many things right. We had turned off our television, so that we would not see replays of the attacks. We made it a point not to discuss our own fears or frightening events in front of Kevin, and we kept disturbing news photos out of sight. Throughout weeks of bomb scares, anthrax attacks and repeated "terrorism alerts," we adhered to a normal routine, albeit in new locations.

Sept. 11 has become one of those dates by which Americans measure time — before, and after. Although my family did not lose anyone in the attacks, our lives have changed profoundly.

My 13-year-old son, Kevin, and I witnessed the attacks from different vantage points in lower Manhattan. From a classroom in Intermediate School 89, a public middle school three blocks north of the World Trade Center, he watched United Airlines Flight 175 slam into the South Tower.

As Kevin fled his school, he saw people leap from the North Tower's upper floors. He had traveled only one block when the South Tower collapsed. For hours that day, he did not know whether I had survived; my office was across the street from the World Trade Center. When we finally were reunited and made our way home that evening, it was to a neighborhood reeling from loss.

The approximately 3,000 students who attended public schools in the neighborhoods surrounding the World Trade Center were immediately dubbed the "Ground Zero kids" by the press. Not only had they witnessed the attacks and massive loss of life up close, but they were displaced from their school buildings for months. The media speculated about the psychological damage they had sustained, whether they would ever recover, and whether it would be too traumatic to return them to their downtown school buildings.

As I struggled to recover from my own initial shock, I became increasingly worried about Kevin. I researched post-traumatic stress and learned that children who have witnessed acts of extreme violence regress to earlier ages. They cling to their parents, are overwhelmed by fears of another attack or of losing a parent, and become withdrawn from family and friends. They experience sleep disturbances, such as nightmares, and exhibit behavioral problems in school or at home. Kevin and his classmates had many of these symptoms.

Parents weren't faring much better. When I compared notes with friends, our symptoms were similar. We couldn't sleep. We had violent nightmares. We were unable to concentrate. We cried easily, often several times a day. We were haunted by the memories of what we had seen. Experts on trauma caution parents to shield children from their own fears. This has been difficult advice to follow in a city that has experienced two terrorist attacks in nine years, and is now consciously bracing itself for more in the future.

Still, as I read about strategies for helping children recover, I saw that my partner, Laura, and I had instinctively done many things right. We had turned off our television, so that we would not see replays of the attacks. We made it a point not to discuss our own fears or frightening events in front of Kevin, and we kept disturbing news photos out of sight. Throughout weeks of bomb scares, anthrax attacks and repeated "terrorism alerts," we adhered to a normal routine, albeit in new locations.

But it was hard to follow the professionals' advice, as I was also suffering from trauma. I didn't want to let Kevin out of my sight. Because I knew, intellectually, that giving into my feelings could hurt his recovery. I struggled to subdue my fear.

Kevin was in eighth grade and had been riding subways alone for two years. We decided that we would accompany him on the day I.S. 89 reopened in a temporary location, 10 days after the attacks, but would allow him to travel on his own once he asked. That happened the next week.

Before parents send their children off into the world alone, they try to prepare them for the worst dangers they can imagine. Years ago, we had taught Kevin how to respond to muggers and other threatening strangers. Now, we prepared him for situations far more perilous. We taught him survival strategies to use in the event of another attack, discussed places where he could seek shelter and gave him a cell phone. Kevin was delighted with the phone and seemed relieved to have a plan, in case the unthinkable once again happened.

Kevin's emotional recovery progressed slowly, until late January, when I.S. 89 returned to its own building. The return of students to the edge of Ground Zero had been a controversial issue. Although I initially had misgivings, I joined a group of parents who worked to advance the return after I saw that Kevin and his classmates desperately wanted to go "home." Ironically, once back at the scene of their trauma, Kevin and his classmates were clearly happier.

Two months later, Kevin's class participated in a mock Supreme Court argument in New York's historic Federal Hall, in a case that questioned whether the government could prevent a newspaper from publishing information because it might be useful to terrorists. Laura and I both slipped away from work to watch the arguments. It was incredibly moving to watch Kevin and other "Ground Zero kids" who had witnessed such a brutal example of terrorism draw on their own experiences to wage a spirited debate about the meaning of freedom.

Kevin is now attending a high school in Brooklyn. Although Sept. 11 and what it represents is never far away, he is much more focused on his new life as a ninth-grader than on this painful anniversary. That is as it should be. The best hope for recovery for the Ground Zero kids is that great gift of childhood, the ability to live fully in the moment.

Susan Hendricks, a Charleston native, is deputy attorney-in-charge for the Criminal Defense Division of the Legal Aid Society of New York. She has lived in New York since 1982.