SANTEE, Calif. — Rhina Paredes-Greeson remembers her son Eric as a happy, healthy teen. That is until one day in July 2009, when he suddenly collapsed onto the kitchen floor.

The then, fifteen-year-old died, due to a heart arrhythmia his parents didn’t know about.

“It’s hard to see his pictures still, it’s been 12 years,” said Paredes-Greeson.

Losing Eric was difficult for Paredes-Greeson, but she resolved to use her grief for good.

“We didn’t not know how to go on,” she said. “(But,) we did not want other parents to go through the same nightmare.”

Eric’s parents formed the “Eric Paredes Save a Life Foundation” the next year, offering free heart screenings for young adults to help families identify potentially fatal heart conditions in their children.

Since 2010, the foundation has helped screen over 37,000 teens, helping nearly 600 people identify cardiac abnormalities that could put them at risk of sudden cardiac arrest. According to organizers, that equates to roughly one out of every 300 kids screened.

The mom of one of these kids, Diana Lee, was present at Sunday’s event. She shared with FOX 5 how her son was able to get surgery to help his heart condition about a month after it was identified by a screening several years ago.

“I was absolutely shocked,” Lee said. “(But,) today, he’s getting ready to graduate college.”

The latest screening event took place Sunday hosted at Santana High School in Santee. About 594 kids and parents came out for Sunday’s the screening.

“It’s really important to do, especially if your kids are in sports, because it can typically save someone’s life,” one attendee said.

For every teen present, they were able to get a cardiac risk assessment, ECG and a consultation with a physician. Attendees were also taught CPR and how to use an automated external defibrillator.

“We do it because heart screening is not part of the pre-participation sports physical or wellness checkups,” explained Paredes-Greeson.

Helping others is the mission behind the volunteer-led effort. More about the Eric Paredes Save a Life Foundation can be found here.

“This is where we get our strength,” Paredes-Greeson said. “That’s what gives us joy and leaves a legacy for our Eric.”