ST. MARYS - A St. Marys airman who made medical history a year ago after sustaining multiple wounds at a remote outpost in Afghanistan has died.

Tre Porfirio, 22, a 2007 graduate of Camden County High School, was visiting friends in Missouri for Thanksgiving when he died unexpectedly on Sunday, his father Karl Porfirio said in a phone interview Thursday.

"He said he wasn't feeling well," his father said. "He just laid down and died."

An insurgent shot Porfirio, an Air Force senior airman, three times in the back at point-blank range on Nov. 21, 2009. Surgeons at two base hospitals in Afghanistan stabilized his condition enough to send him 8,000 miles to Walter Reed Army Medical Center about 92 hours after he was wounded.

Surgeons removed what remained of his pancreas, packed the damaged organ in ice and sent it to the diabetes research institute at the University of Miami Miller School of Medicine. A team of surgeons at the university spent six hours removing islet cells that produce insulin and purified them before sending them back to Walter Reed a day later.

The cells were injected into Porfirio's liver, making it the first time doctors successfully isolated and transplanted insulin-producing cells following the complete removal of the pancreas. The procedure made it possible for his liver to produce insulin.

Karl Porfirio said his son had some nutritional complications that left him without an appetite at times. Other days, his son had a good appetite and felt healthy.

"It was about 50-50," he said. "It was three steps forward and two back. He tried his best."

He said the procedure gave his son a year of life he may not have had otherwise.

"He was on borrowed time," he said. "He lived long enough to witness the birth of his son, Landon, nine months ago."

Karl Porfirio thanked the medical staff at Walter Reed; airmen at Wright-Patterson Air Force Base in Ohio, where a memorial service was held Thursday; and the many supporters his son had in Camden County and across the nation.

"He was my hero," he said. "But he was also my son.

A funeral with full military honors will be held today in Knoxville, Tenn., his hometown. A memorial service will be held in St. Marys but a date has not been set.

gordon.jackson@jacksonville.com, (912) 729-3672