When a Navy medic from Zimmerman, Minn., nearing the end of his tour of duty in Iraq died on Sept. 11, 2004, family members were told he died of natural causes.

They now know differently: Petty Officer 3rd Class David A. Cedergren, 25, was electrocuted while showering, the third U.S. service member to suffer that fate in Iraq.

And the deaths are now part of a wider criminal investigation, part of a probe that's looking into a total of 18 electrocutions that have occurred in Iraq, in a variety of circumstances.

"Obviously it brings some closure to what we all originally thought had happened to David," said Cedergren's brother, Barry. "But the hard thing is you start to heal knowing one thing, and then the wounds reopen and you have to look at things in a different way."

The Associated Press reported Monday that late last year, the Armed Forces Institute of Pathology changed the cause of Cedergren's death to "accidental," caused by electrocution and inflammation of the heart.

The Naval Criminal Investigative Service has reopened an investigation into his death, Ed Buice, an NCIS spokesman, said Monday. He would not comment on specific evidence in Cedergren's case.

Barry Cedergren of Ramsey said family members initially suspected that David had been electrocuted because, according to reports shown to the family, witnesses told investigators that some service members had reported suffering electrical shocks in the shower. "It showed that these guys were getting zapped, so it made us wonder," he said.

Last year, the staff of Sen. Norm Coleman, whose term expired Jan. 3, contacted the family to say the investigation had been reopened. In November, the family received an amended death certificate stating the actual cause of death.

"Somebody dug a little deeper and -- oh, yeah, that was the cause after all," Barry Cedergren said. "In some ways, you sit and wonder if they knew all along and bypassed the real cause. Who knows?"

Cedergren, the 11th Minnesotan to die in Iraq, was found unconscious in an outdoor shower stall at Camp Iskandariyah. He was taken to a nearby military medical facility, where he was pronounced dead.

At the time, family members said they were not aware that Cedergren had any underlying health problems. "They said he had a chest cold, a virus," Barry Cedergren said.

David Cedergren grew up in Zimmerman and attended school in Elk River. He liked cars, motorcycles and tae kwan do, and was what family members called "a fanatic" about exercise.

He was sent to Iraq in March 2004 and was scheduled to be rotated home a month after his death. He had planned to study to become a nurse.

Cedergren's death is among 18 electrocution deaths under review as part of a Department of Defense inspector general inquiry, the AP reported.

Sixteen of those who died were U.S. service members. Two were military contractors. According to the AP, improperly installed or maintained electrical devices have been blamed in some of the deaths, while accidental contact with power lines has been a cause in others.

"We're still looking at all of our options and aren't really sure what we'll do next," Barry Cedergren said. "There's still a criminal investigation to finish. It doesn't change the fact that we had to ask and ask and ask. We might have reacted a lot differently if we'd known the truth from the start."

The Associated Press contributed to this report. Bob von Sternberg • 612-673-7184