(CNN) The communities of Parkland and Newtown are mourning the suicides of two students and a parent this week. The ongoing grief in the these cities scarred by gun violence is now mixed with a need to remain vigilant for signs of distress in close relatives and friends.

The events highlight the long-term impact of living through school shootings.

"The Parkland survivors have been heroes in their advocacy efforts since the tragedy, but the deaths of these students are a sobering reminder that they are not only young advocates, but also trauma victims and gun violence loss survivors," said Micheal Anestis, associate professor of psychology at the University of Southern Mississippi and co-chair of the American Association of Suicidology.

The National Center for PTSD estimates that 28% of people who have witnessed a mass shooting develop post-traumatic stress disorder or PTSD, and about a third develop acute stress disorder.

Michael Dorn, executive director of Safe Havens International, points out that there were also concerning patterns between the attack at Columbine High School and a number of suicides involving former students, as well as family members of victims killed in the attack, adding that although the pattern was seen, it is challenging to attribute it solely to the mass shooting.

Despite the statistics, and the disheartening recent events, surviving a mass shooting does not mean children, teens and communities are permanently damaged, explained Dr. David Schonfeld, director of the National Center for School Crisis and Bereavement and a pediatrician at Children's Hospital Los Angeles.

Recovery, Schonfeld insists, should be the expectation and the common goal to be achieved. It starts with understanding that communities' world views have been challenged.

Children who have lived through mass shootings, as well as children in communities nearby and far away, can experience what Schonfeld calls the loss of the assumptive world upon learning about the events.

"There are certain assumptions that people every day make that allow them to feel safe and secure in a world that does have a lot of dangers in it," he said. When a child hears or lives through an event that challenges the notion of safety in a school, it makes them question all the other assumptions they have about the world, Schonfeld added.

The loss of the assumptive world, on top of the actual trauma, can set off a cascade of events.

Immediately after a traumatic event, Schonfeld explained, children and teens can have difficulty concentrating and sleeping. This in turn may lead to a decline in academic performance, which then means children and teens are experiencing academic failure for the first time. This may bring additional distress and lead to some irritability.

The irritability can then lead to impaired social interactions, making people more suspicious and less trusting, he added, with repercussions for years.

The second year may be harder

Schonfeld explained that the aftermath of surviving a mass shooting or a similar traumatic effect should be thought of in terms of the grief and the trauma.

For those who lost a loved one, the grief can persist for years, with people continuing to reprocess those loses as they move forward in their life, he said.

"Then there's a trauma from being involved in an event where a threat was made against your life," he added.

Both grief and trauma can be long-term, and sometimes, the second year can be more difficult than the first.

"In the first year, there's a lot more support that's provided in general by friends and families. There's the expectation that the first Thanksgiving, the first holiday, may be very difficult. Families and friends rally together, and the expectations are sometimes lower. 'I just want to make it through my first Christmas,' " Schonfeld said.

The loss then persists the second year, but the support system may not be as strong, which results in a more difficult time coping.

Given a choice, survivors may choose to feel guilty over feeling powerless

Guilt is extremely common after the death of a loved one or after a crisis event, with people trying to point to what they did wrong, Schonfeld explained. At least in an unconscious level, survivors may try to find what they did wrong.

"If you can say to yourself, 'if only I had been there or if only I had been more cautious or if only I had done something or not done something that I did.' That gives you the illusion that you can control future events by simply not making that mistake again," Schonfeld said. "The alternative is understanding that you had no role in this. You could not prevent it. Therefore, you can't prevent it from happening again," he added.

Despite the guilt, the loss of control and potential repercussions, recovery is possible and should be the goal.

The expectation is recovery, not activism

"You want to set the expectation for recovery, while providing sufficient support to promote that recovery and having a backup so that if individuals are struggling, we provide them even more support and assistance."

Some individuals experience what is called post-traumatic growth after events like mass shootings, finding a renewed sense of purpose or a greater sense of spirituality. But that should never be the expectation, Schonfeld said.

"We do have skills and strategies [to help children and teens] as we do with adults," he said. "We need to make them widely available and encourage people to take advantage."

What parents can do

"This is a time to spend more time with your family, to hold those close to you closer," Schonfeld said. He recommends asking kids what they've heard, how they feel and how we as adults can help them cope with their feelings.

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This is not a time to tell kids or teens not to worry or to provide a false sense of reassurance, but rather to validate their feelings and share concerns with them, he added.

Jonathan Singer, family therapist and associate professor at Loyola University Chicago School of Social Work, also recommends slowing down and spending more time with kids and teens. Simply being present can provide a window of conversation and can help parents be attuned to signs their kids are not coping well.

These signs include drastic changes in behavior or mood, sleep and appetite disturbances, as well as any expression of a sense of hopelessness, he added.