NORTH OLMSTED, Ohio -- Nicholas DiMarco was 18 when he died from a dose of heroin laced with fentanyl.
He left behind a grief-stricken father tormented by questions.
"The biggest mistake that I made I looked at my son and I thought of it as a rational, normal person," Fred DiMarco said. "I was like, well he's going to quit. If he doesn't quit, he's going to go to prison for three years. Who would take that risk? He's going to quit. It's killing people. Who would take something that's going to kill them?"
After 18-year-old Nicholas DiMarco died March 9, 2015 from a dose of heroin laced with fentanyl, his father made it is mission to keep other parents from experiencing a similar loss.
"Whoever put that fentanyl in that heroin killed my son," Fred DiMarco said in an interview at his North Olmsted home. "My son had a disease of addiction and he was looking for heroin, not fentanyl. Those people should be tried for murder."
The state of Ohio currently allows prosecutors to charge people who supply drugs to people who die of overdoses with involuntary manslaughter.
Nick DiMarco was an intelligent student and a gifted athlete who aspired to become a personal trainer, his father said. He had a charming smile and was popular among students at North Olmsted High School.
But behind his piercing blue eyes, Nick DiMarco was hiding anxiety and depression, his father said. That's what led him to use pills, and to eventually become addicted to heroin.
Nick DiMarco was kicked out of high school in September 2014, his senior year, his father said. Another student told a teacher that Nick DiMarco had a gun in his car. It was actually an airsoft gun.
Security guards searched Nick DiMarco and found illegal pills.
The expulsion made him plummet into a depression, and to use heroin to cope, his father said.
Nick DiMarco finished his high school education online and graduated with honors. He worked part-time jobs at UPS and at the airport as a valet.
He was set to start working full-time at a local oil-changing station the morning after he died, his father said. He had bought his work clothes and was excited for the new gig.
But he never made it to the job.
His twin brother found him unconscious in the bathroom about 10:30 p.m. He called 911 as Fred DiMarco tried to give his son CPR. He was one of the 228 people who died last year in Cuyahoga County from drug overdoses attributed to heroin, fentanyl or a combination of both drugs.
"It was very difficult because I didn't save him," Fred DiMarco said. "I talked to doctors, EMS and firemen until they finally convinced me that nobody short of Jesus Christ could have brought him back - that he had been there too long."
Nick DiMarco had been in a treatment program through Cuyahoga County Juvenile Court. That hadn't worked.
They wanted to admit their son to the Glenbeigh rehabilitation hospital in Ashtabula County, but since Nick DiMarco was on probation, he wasn't allowed to leave the county. His probation officer never returned Fred DiMarco's calls to discuss making those arrangements.
Fred DiMarco said he and his wife still think about what they could have done to save their son.
"There are no words in the human language to explain the pain and grief of losing a child," Fred DiMarco said.
Now, Fred DiMarco spends his free time attending and speaking at rallies to raise awareness about the dangers of heroin addiction. He talks to families whose loved ones are addicts, and even mentors some of Nick DiMarco's friends who are struggling with addiction.
He attends classes and seminars to learn as much as he can about heroin addiction, in the hope that he can save someone else from dying the way his son died.
"Until you understand the disease of addiction and what it makes you do, its difficult to help people," he said.
"I don't want another Nick, and I don't want another me."