SAN DIEGO -- A 62-year-old father returns home to San Diego after making a life-changing decision following the death of his son in Iraq and talks to 10News about his war experiences.

Lt. Cmdr. Bill Krissoff is a U.S. Navy corpsman who has just returned to San Diego after a tour of duty in Iraq. He was assigned to an emergency surgical facility in the Anbar province.

"(I was) honored to be able to serve in theatre; it was truly a privilege," said Krissoff.

After decades as an orthopedic surgeon in private practice, Krissoff walked away from the life he knew and put on a uniform to perform combat medicine in a war zone.

"The Marines I took care of were easily the most motivated and appreciative patients I've ever cared for," said Krissoff.

For Krissoff and his wife Christine, life changed in December 2006 when their oldest son, 1st Lt. Nathan Krissoff, was killed by a roadside bomb in Iraq.

"I've viewed his work as unfinished in Iraq … my way of thinking ... I was carrying on to finish his unfinished task," said Krissoff.

Even with their younger son, Austin, deploying with the Marines in Iraq, Krissoff contacted a Navy recruiter to volunteer his service -- at 60 years old.

"After he checked with his command, he said it would be pretty unlikely that the Navy would take me," said Krissoff.

But reality ran into fate, and Krissoff found himself face-to-face with President George W. Bush, who was attending a gathering of families who had lost loved ones in the war.

Krissoff said just enough. "I'd like to join the Navy medical corps and serve, but they told me I'm too old."

Two days later, Krissoff received an age waiver and his journey began. He first learned Navy rules, regulations and medical protocols. He then treated injured Marines in a remote environment.

"It's a very harsh environment. Temperatures are extreme, air quality is poor; it's a rough life for the Iraqis," said Krissoff.

There were no trees, not a blade of grass where Krissoff was assigned. There was nothing but sand, barriers and walls.

"I don't think anyone can understand a deployment without having deployed," said Krissoff.

Krissoff got to see Austin a couple of times in Iraq, but Nathan was never far from his mind.

"He had a great sense of humor, keen intellect, charismatic, great athlete, piano player, natural leader, very special," Krissoff said of Nathan.

Christine Krissoff watched all the men in her life put service over self.

"I'm very proud of my three men. I think they're all very tough and capable guys," said Christine Krissoff.

The family's sacrifice continues, even though Krissoff is back at Camp Pendleton's naval hospital now and Austin is back from Iraq. A deployment to Afghanistan is still possible, but the family will be together this Thanksgiving, thankful for having the opportunity to serve.

"Honor those who have made the ultimate sacrifice and those who have been injured. But more importantly honor the concept that you need to give back to your country," said Krissoff.

Krissoff said he understands much better now the life his son chose, and yet he knows his own experience was still far less challenging by 2009 than the volatile situation his son faced in 2006.