Whether he was in the classroom helping fellow students grasp the fundamental concepts of engineering, or at a campsite surrounded by his Sigma Phi Epsilon fraternity brothers, Ryan Marcia seemed to never stop thinking of the people around him.

Marcia — who graduated from OSU with a degree in mechanical engineering in 2012 and was working as a response advisor at ExxonMobil — was hit by a car at about 12:30 a.m. on Sunday while he was crossing Summit Street at 18th Avenue, a Columbus Division of Police press release stated. Marcia, 24, was taken to the OSU Wexner Medical Center in life-threatening condition.

He died at the Medical Center on Sunday at 10:18 p.m., according to a Columbus Police release.

Some people who knew Marcia said he will be remembered as being a selfless human.

“He was just a really loyal friend,” said Matt Lehrer, a 2013 OSU graduate and chapter president of Sigma Phi Epsilon while Marcia was a member. “He would give you the shirt off of his back, he really would.“

Marcia was a National Merit Finalist and a valedictorian of Gahanna Lincoln High School who attended OSU from 2008-12. As an undergraduate student, Marcia was a member of the Order of Omega Honorary, Romophos Sophomore Class Honorary and an OSU Honors Ambassador, according to his LinkedIn profile.

For three years as an undergraduate, Marcia worked as an in-class teaching assistant within the OSU College of Engineering.

“Ryan was in my honors engineering class in Autumn 2008 and he later was my undergraduate teaching assistant for the same class,” Lisa Abrams, interim director of diversity and outreach for the OSU College of Engineering, said in an email. “He was always a very positive person, always very respectful and very professional in class.”

In the summer, Marcia volunteered as a teacher with the Summer Honors Institute, where he helped students design and plan their freshman projects.

“He had a great work-life balance,” Lehrer said of Marcia’s academic and extracurricular responsibilities. “He would work extremely hard, but also … he struck a balance between work and play and I always admired that quality in Ryan.”

Lehrer said he will never forget the “fierce loyalty” that Marcia displayed both as a leader and as a friend.

“In my sophomore year, I was on a committee where I helped plan a retreat … a canoeing and camping retreat for the fraternity brothers. So we showed up at the place, (but) I forgot the check at home (for) $1,500,” Lehrer said. “So I go around and ask all of these guys and no one can pay and no one could help me out, so finally I got to Ryan. He just said that he would pay for the whole thing, $1,500 on his card. No questions asked.”

The investigation into Marcia’s death is still ongoing, according to a release.

Lehrer said he will miss Marcia’s intense passion for life and hopes that his legacy as a “charismatic leader” lives on.

“He was bold and I think he just got a lot out of life. He really stood up for what he believed in,” he said. “And if he could pass that on, I think he would say, ‘Don’t be on the sidelines and hide. If you believe in a cause or are passionate about something, then really go for it and be bold and make it your own.’”

Correction: A prior version of this article stated that Ryan Marcia was chapter president of Sigma Phi Epsilon while he attended Ohio State. In fact, Matt Lehrer was chapter president of Sigma Phi Epsilon while Marcia was attending OSU.