Virginia Beach, Va. - Already a talented swimmer, Cameron Gallagher, 16, decided to take on running as a new challenge.

After spending weeks training, the teen from Richmond traveled to Virginia Beach to take part in the Shamrock Half Marathon Sunday.

"Her entire mission was to enjoy the race and accomplish something and spread that cheer on to other people," said her dad, David Gallagher.

Her parents were there to cheer her on.

Gallagher says the race seemed to be going well at first, but at the 10-mile mark, his daughter was noticeably tired.

When she crossed the finish line, she gave her friend a hug, then collapsed. Her heart had stopped.

Her dad says doctors did everything they could, but they weren't able to save her.

Gallagher says she although she was young, she was an inspiring person, and he hopes she can continue to inspire others even though she's gone.

"One message we want everyone to know: Cameron's last moments were joyous and happy," Gallagher said. "Her friends, her family and the entire Virginia Beach community was out there with her celebrating that, and I can't imagine a better way to feel in the last moments of a lifetime, is to feel accomplishments and set a goal. And I hope everybody takes that message and uses it in their own life."