The Rev. Paul McCullough, a pastor at the Willmar Assembly of God, still remembers vividly where he was and what he was doing on that September morning 10 years ago when terrorism hit home in the United States.
He was sitting in a café drinking coffee when there was a news bulletin: A plane had flown into the World Trade Center.
His first mental picture was of a small aircraft. But as the images from New York City, the Pentagon and Pennsylvania began to pour in, McCullough, who's a volunteer chaplain for local law enforcement and their families, realized the full scale of what was happening.
He remembers the shock and disbelief. "I still see the pictures over and over of the buildings coming down," he said.
As the anniversary approaches, his feelings are mixed. Will it be a time to reflect or a time to rake up painful wounds?
"It's an opportunity for us to stop and meditate," McCullough said.
Ten years later, have we recovered emotionally from an event that seared the collective national soul?
For the past decade researchers have been exploring this question and have come to a reassuring conclusion: Most Americans are more resilient than they think.
"Our country's come a long way in 10 years," said Brenda Wiese, coordinator of The Grief Center at Rice Memorial Hospital.
Some of the most compelling lessons can be learned from many of the families of the 9/11 victims, she said. "They have shown that with time and with patience and being gentle with themselves, they can move forward. Life will look different. It might not be the same or feel as safe but it can be good again."
In the immediate wake of 9/11, many psychologists predicted the trauma would have widespread, long-lasting effects. But multiple studies over the past decade have found post-traumatic stress disorder or other trauma-related issues such as substance abuse or depression in only a minority of individuals.
Those with the most direct experience of 9/11, either because they were there or had someone close to them who was there, were the most likely to develop trauma-related problems.
McCullough likened it to the grief that's experienced after a death. "The closer your relationship to it, the longer it lingers," he said.
Psychologists have debated whether "remote trauma," or trauma that's witnessed on TV instead of being experienced firsthand, can give rise to PTSD and post-traumatic physical ailments. A provocative -- and controversial -- new study published this summer suggests that it can.
Whether Americans were exposed directly or not, however, the terrorist attacks left a deep emotional imprint, Wiese said. "This was an event that was happening in our borders. Here was something where we felt threatened and invaded. If it can happen there, maybe it can happen here ... This was something totally beyond our control."
One thing that has been learned about trauma is that the response to it is often individual. Previous losses or hardships, ill health and substance abuse all can make people more vulnerable to post-traumatic difficulties.
Absence of family or social support also makes a difference, Wiese said. "Sometimes it's in the talking that we can work through the trauma and find a way to move beyond it. For people that don't have the social support, that's hard to do."
A handful of recent studies suggest that brain chemistry might also play a defining role.
"Some people are just able to handle stress and trauma than other people are," Wiese said. "We all have our own unique way of dealing with trauma. Every one of us went through trauma after 9/11. Some of us can move on. Some people take more time to recover than others. Some people are scarred and (will) have difficulty the rest of their lives."
McCullough remembers the one-year anniversary of 9/11. Back then, the wounds were "still very fresh," he said.
Now that 10 years have gone by, how will we feel? McCullough hopes the anniversary will be a time for thinking and for rediscovering the national sense of togetherness that emerged in the immediate aftermath of the terrorist attacks.
"What do we learn from it?" he said. "What have these 10 years taught us? There've been wars. Lives have been taken ... What can we glean from this that's positive and move on?
"What can we learn from the past and what can we invest in the future?"
One outcome of the terror attacks was that many Americans became less trusting, Wiese said.
As they remember 9/11, this can be a time for them to connect with their community, she said. "One of the lessons for us individually, but also as a society, is to reach out, to not try to handle it alone. All of us can look around and see who isn't reaching out. Who is it in our lives that maybe needs us to reach out to them?"