Gregg Zoroya

USA TODAY

Kathy Platoni can never forget the fatally wounded soldier who died in front of her during the mass shooting that left 13 dead at Fort Hood, Texas, seven years ago. She still suffers from post-traumatic stress disorder from that day.

A clinical psychologist who was an Army reservist in 2009, Platoni was in a building directly adjacent to where those shootings occurred when a mortally wounded Army Capt. John Gaffaney was carried in. She knelt down to see his last breath. Watching coverage of Sunday's massacre at the Pulse nightclub in Orlando brought it all rushing back.

"There are so many psychological casualties after an event like this." Platoni said Monday. "I cried a lot of bitter tears yesterday. I just felt so helpless and so filled with despair."

Behavioral health experts caution that a second wave of suffering can flow from such violent events, as survivors and first responders — such as the police officers who fought their way into the Pulse early Sunday — struggle with what they've witnessed.

"This is like war. This is serious trauma," said Barbara Van Dahlen, founder and CEO of Give an Hour, an organization set up to help traumatized soldiers. "No one, no matter how much training you've had, can prepare yourself for these kind of horrific experiences."

Orlando shooting victims summed up America’s rich diversity

Orlando SWAT team members stormed the club where gunman Omar Mateen was barricaded and killed him in an exchange of gunfire. The bodies of dozens of the 49 patrons he murdered lay strewn about the building as police spent hours ensuring there were no explosives left inside by Mateen and then processing the crime scene.

It was a horror very similar to what police officers in Connecticut encountered in 2012 at the Sandy Hook Elementary School, where 20 children ages 6 and 7 and six adult staff members were shot to death by a lone gunman, who then took his own life.

A lawyer for the police union in Connecticut, Eric Brown, estimated that perhaps 30 police officers struggled with emotional issues in the wake of that tragedy, including PTSD.

"There was an expectation from at least a part of the population that said, 'Well, they're police officers. They should expect this type of thing. Tough it up. Get a thicker skin,'" Brown said. "But who could reasonably deal with seeing 50 dead bodies (in Orlando) or 20 dead children?"

Behavioral health experts say it is common for people to have intense memories of traumatic events. But when those memories become intrusive and involuntary, the result can be PTSD, an illness that leaves a person feeling anxious, isolated, depressed and often turning to various forms of self-medication, such as drugs or alcohol, for relief.

Former Colorado police officer John Marx, executive director of the Law Enforcement Survival Institute, which offers resiliency training to police, said studies show that anywhere from 13% to 35% of police officers suffer PTSD, rates comparable to those found among troops who have been to war.

"One of the issues in both populations," said Marx, "is you're looking at a career where you're supposed to be tough, and reporting emotional trauma can seem like it's going to affect your career. And so many, many people endure the trauma without reporting, without seeking help."

There have been initial indications of emotional support for the survivors of the Orlando shootings. Heart of Florida United Way is offering therapy. Counselors have been made available for University of North Florida students. The Orlando VA Medical Center is providing mental health counselors.

Give-an-Hour founder Van Dahlen, who has launched a national initiative to change mental health culture called "The Campaign to Change Direction," said that after what happened in Orlando, it is also important for families and co-workers to be supportive of those impacted by the shootings.

"It doesn't mean everyone will have long-term post-traumatic stress. We shouldn't be thinking that way or acting that way," Van Dahlen said. "But we want to be in a position where we're thoughtful, mindful, attentive and incredibly responsive and supportive to those affected."

She said that people can recover from their emotional trauma. "But it's more likely to happen if we deal with this above-board rather than ignoring it."