Sam Granillo remembers when, as a kid, he finally outsmarted his bigger and older brother.
"He would chase me around the house," Granillo says. "I would go into my room and slam the door, but I knew I couldn't keep it shut because he could overpower me."
Then, he had his Eureka moment.
"One glorious day I wedged my toes at the bottom corner of the door," he said. "No matter how hard he tried, he could never get into my room."
Years later that memory would roar back in a split-second flash, as Granillo-running for his life from the sound of gunfire and explosions- found himself cornered in a room with no lock on the door.
"I knew the best way to keep the door shut was to wedge my toes at the bottom of the door," he says.
Just a few moments before, the Littleton, Colo. high school junior had been eating a peanut butter and jelly sandwich in the cafeteria when two students unleashed a deadly attack at a place now indelibly linked to one of the country's most horrific murder sprees: Columbine High School.
Granillo and 17 others were trapped in that cafeteria kitchen office for about three hours until a SWAT team rescue. By the time April 20, 1999, was over, Eric Harris and Dylan Klebold had murdered 12 students and a teacher, and killed themselves.
Thirteen years later, Granillo is a film school graduate of the University of Colorado at Boulder. He is 30 years old and works on commercials, films and television shows like "Rescue Renovation" and "American Idol".
Despite the passage of time, Granillo says he is still haunted by nightmares, panic attacks and depression. Many of his former fellow classmates, he found, are suffering similar symptoms but finding affordable mental health services hard to come by. He says some of his friends have gone into deep debt paying for counseling.
So now, Granillo is putting his filmmaking skills to work, producing and directing the first documentary about Columbine by a student who was actually there.
"I started thinking about what I needed to do to create this documentary to raise awareness that we need help," he said.
Granillo isn't exactly sure yet what form that help should take - perhaps a foundation or organization that offers free counseling for anyone suffering from Post Traumatic Stress Disorder, or PTSD.
Making the film, Granillo says, is also part of a journey to help Columbine survivors talk about their experiences. He's hoping to take advantage of a "thaw" he senses among some Columbine students who have rarely - if ever - spoken publicly about that day. Some are now opening up to him for the first time.
"There's a change happening," Granillo believes. "People, up to this point, have avoided even mentioning that they're from Littleton because they don't want to even talk about it. Everyone is becoming comfortable with admitting they need help. That's something that's really changing. It's becoming unburied. It's becoming un-taboo to talk about. Being able to talk about it is a first step."
Granillo says he has already started recording interviews and has put together short preview trailers. So far he's raised less than $20,000 of the $250,000 he needs to complete the project. One major expense: travel. Many former Columbine students no longer live in Colorado, or even the United States.
Another expense: animators. Rather than using the much-repeated Columbine footage shot from TV news helicopters, Granillo says he's making a stylistic choice to rely heavily on animation to depict the events of April 20.
"There's no reason to show the violent images," he said. "The biggest thing about this is moving forward. And everything in the past needs to be animated because it gives that feeling that it's real, but you can't touch it anymore."
While Granillo says his status as a former student gives him a certain amount of built-in credibility, that does not get him a free pass from the Columbine community, which is still understandably sensitive about how the event is portrayed.
"It's intimidating," Granillo says of becoming a public face of Columbine. "I'm worried I will do something wrong. This isn't about me, it's about all of us."