At 6’4” tall and about 290 pounds, onetime heavyweight prospect Preston Hartzog, a native of Bogalusa, Louisiana, was a big man. But all who knew him insisted that his fighting heart and his unbridled enthusiasm for life dwarfed his physical stature.

That is why his friends and family were so shocked when the 29-year-old Hartzog, who was nicknamed the “Bogalusa Boogieman,” died suddenly on June 21. He was inside of his Los Angeles apartment when he went into cardiac arrest. There is a history of heart trouble in Hartzog’s family.

His father, Seymon, passed away from complications from a heart attack when he was just 54 years of age. And two years ago Hartzog’s sister, New Orleans-based boxing manager AnnaBeth Goodman, who is in her late thirties, had surgery to implant a mechanical heart valve.

Hartzog’s cardiac arrest was caused by a rare disease called sarcoidosis, which is characterized by the formation of nodules in the lymph nodes, lungs, bones and skin. It is most successfully treated by steroids.

However, when it settles in the heart, as it did in Hartzog’s case, steroid treatment is not effective. Even if the insidious disease had been detected in advance, which it was not, his chances of survival would have been slim to none.

“I’m still trying to get used to life without him,” said his sister, who is married to actor John Goodman. “Even though heart problems run in our family, Preston was the last guy you’d expect to have a heart attack.”

Hartzog was inspired to box by his father, a maniacal boxing fan and jack of all trades who had been a football hero at Southeastern Louisiana University. When Preston was 11-years-old, he journeyed to the Bogalusa YMCA and began training with Jimbo Stephenson.

Realizing he had a diamond in the rough, Stephenson took Hartzog to New Orleans to be fine-tuned by former light heavyweight champion Willy Pastrano. Before long, Hartzog was learning his craft the hard way by sparring and competing against inmates at the Washington Parish Correctional Institute.

Hartzog joined the United States Army in 1995, and was soon accepted into the prestigious World Class Athlete Program in Colorado Springs. The program had prepared Ray Mercer, Andrew Maynard and Anthony Hembrick for Olympic competition.

When Hartzog’s father died suddenly in 1996, the young fighter was spiritually and emotionally shattered. Even as he won one military title after another, it was hard for him to find much joy in his success.

“It was sad not to have my father around to share it with,” Hartzog told me a few years back. “I used to see guys at the national championships with their fathers in the corner and I would get very upset. I envied them. My father always said I had a great talent, but he never got the chance to really see it.”

There were others, however, who did have the pleasure of bearing witness to Hartzog’s immense talent. One such person was former WBA heavyweight champion Tony Tubbs, who trained Hartzog in the early days of his pro career.

Fighting professionally from June 2001 to August 2005, Hartzog compiled a record of 15-1-1 (4 KOS). After losing a six round decision to journeyman Willie Chapman in his last fight, he decided to forsake boxing and embark full-time on an acting career.

He landed several small stage and screen roles, including the role of a New York firefighter in Oliver Stone’s soon to be released “World Trade Center.” Just a week before his death, Hartzog received a coveted Screen Actors Guild (SAG) card.

“Preston was a helluva fighter,” said Tubbs. “For such a big guy, he had good hand speed. But he got frustrated with the fight game and wanted to pursue acting. Once boxing is in your system, it’s hard to give up. But Preston would have been successful at anything. He was a winner.”

Another heavyweight who thought the world of Hartzog was well-traveled journeyman Ross Purrity, who is best known for handing current IBF champion Wladimir Klitschko his first career loss. When he and Hartzog first met at a Houston gym, they took an instant dislike to each other.

Purrity laughs about that now because one day after their initial meeting they were fast friends.

“We had similar personalities, so it was a boxing thing,” explained Purrity. “When we first met, I guess we were wary of each other. But the second time, the very next day, we just clicked. I thought Preston had a great future in boxing.”

Moreover, said Purrity, “he was real smart and very interested in a lot of things, so he had options. He chose boxing, which made me think he would be successful. When he chose acting, I knew he’d be successful in that too. It got to the point where we never lost touch. We spoke at least once a week, right up until his death. This sounds strange, but as much as I feel sorry for him and his family, I also feel sorrow for myself because I lost such a good friend.”

“Preston was such a kindhearted guy, and I’ll miss his big, friendly smile very much,” said cruiserweight Clint Calkins of Muscatine, Iowa, who doubles as a matchmaker.

“When I first met Preston, he made me feel like I’d known him for years. He was kind and compassionate to everyone he met, and he had one of the kindest hearts for such a big guy in a brutal sport. I still expect to get a phone call or e-mail from him. I’ll miss him.”

Although he had been on this earth for less than three decades, it is obvious that Hartzog left an indelible impression on all he came in contact with. While filming his scenes in “World Trade Center,” his sister said he was cast alongside some real life New York firefighters. Some were familiar with his boxing career, which tickled Hartzog to the bone.

“He was really excited about that,” said AnnaBeth. “He was also really excited that he was getting parts without my husband’s help.”

It is obvious that there was much for Hartzog to be proud of in his short life. He served his country in the armed forces, was a devoted partner to his beloved fiancée Tracy Brenes, and found a degree of success in boxing and acting, which are arguably the world’s two toughest vocations.

In a cruel twist of fate, “World Trade Center,” which quite possibly could have set the tone for his future livelihood, is slated for general release on August 9, the day that Hartzog would have turned 30. His sister can’t help but cry when she thinks of the irony of it all.

“Preston had decided to retire from boxing to pursue acting,” she said. “Things were moving along so nicely for him. Nobody deserved success more than he did. Preston was never afraid to try something new, no matter how challenging it was. He was a real daredevil, absolutely fearless, whether it was boxing, scuba diving or jumping out of airplanes.

“He wasn’t afraid of turning 30 at all,” she continued. “He had his whole life ahead of him. I will always look at the way he lived his life, and he will be an inspiration to me forever.”