Don Carey will never forget an August day in 2004 when he heard a knock on his door.

"I remember it until this day like it was yesterday,” Carey said. “I close my eyes to go to bed and that’s what I see, two Marines standing on our doorstep."

They were there to tell Carey and his wife, Michele, that their son was killed in the line of duty.

Marine Corps Corporal Barton Russell Humlhanz, 23, was on a military policeman patrol in Iraq when his vehicle was struck by an IED.

"It’s a feeling you wouldn't wish on your worst enemy, it’s not like anything we have ever experienced,” Michele Carey said.

Humlhanz was on his second tour of duty when he was killed. He joined the Marine Corps just weeks after September 11, 2001.

"The main thing we try to focus on is that we try to conduct our lives living in his memory and honoring his service,” Don Carey said.

That’s why the Careys joined other families who have lost loved ones at the 8th Annual Run for the Fallen, hosted by Marine Families, at Veterans Memorial Park.

The annual event honors Florida fallen military men and women who have paid the ultimate sacrifice during the wars in Iraq and Afghanistan.

More than 5,000 participated in this year’s event, which started Saturday night with a candlelight vigil and finished Sunday with one mile, 5K and 10K races.

Last week, a fallen memorial tribute, made up of individual crosses for each fallen hero, was put up in the park.

Before the race, 10-year-old Bryor Hess stood at the memorial, silently watching over the cross with his dad’s picture.

"He was really funny, he was a really good dad at the time,” Hess said. “I know he loved me."

Army Specialist David Hess was killed in Afghanistan in 2010, when his son was just four years old.

Each runner in Sunday’s race was assigned one of the heroes and wore their names and pictures proudly as they ran.

Janet Pacheco-Hodges said each year she researches the hero she is assigned to and posts a picture of him or her on social media.

"This is the treasure that you take with you and you keep them,” Pacheco-Hodges said.