Just because it's in your head, doesn't mean it's not real, according to co-founder of The Rebels Project, Heather Martin.

"I've talked to a lot of the people from Virginia Tech, some of the kids from Newtown and the families there and you don't have to be injured to be a survivor," Martin said.

Martin and others who were at Columbine on the day of the tragic shootings started The Rebels Project after the Aurora theater shooting in 2012. 

"After Columbine and after any tragedy, the money comes flying in. People are so willing to help and so willing to donate and it's awesome," Martin said. "But, after a certain amount of time, the money goes away."

The money goes away, but the problems don't especially for people who may not have been physically injured. Martin was trapped in the choir office at Columbine on April 20, 1999. But, she says years later the experience still affects her and other people who were there that day.

"When you're surrounded by people who don't understand, it's so easy to bottle it up and not want to talk about it and not express it," Martin said.

The Rebels Project has taken over the Resolute Brewing Company in Centennial to raise money to help people who've been through mass trauma to get help for Post Traumatic Stress Disorder.

"Because it's in your head, it's even harder to get a grasp around why you might be suffering," Martin said.

Zac Rissmiller is not only part-owner of the Resolute Brewing Company, he is a Columbine survivor who dealt with depression for years after the shooting.

"I have a thing called 'Survivor's Guilt'," Rissmiller said. "I was supposed to be there, but wasn't."

Rissmiller cut class that morning and went to a Taco Bell.

"Maybe my irresponsibility saved my life," Rissmiller said.

But, it didn't save him from suffering.

"You didn't have to be there to have a lot of friends die in one day," Rissmiller said.

Martin says this fundraiser entitled, "Rebels with a Cause", will raise money for her group to hold monthly meetings with survivors and bring other mass trauma survivors to Denver for support.

"The problems are really life long for many survivors," Martin said.

If you want to find out more about the fundraiser, click here: http://therebelsproject.org/