Michael Joseph Strange was a Navy SEAL, an accomplished triathlete, and a striver already studying for a post-military career as a nurse. But when his life was cut short Saturday in a helicopter crash in Afghanistan, relatives say, he was doing exactly what he set out to do seven years ago: protecting his country.

"He was an ordinary Philly kid who loved his cheesesteaks and loved the Eagles," said Strange's aunt Maggie O'Brien, who was among dozens of relatives and friends who gathered to grieve over the weekend at his mother's Northeast Philadelphia rowhouse. "Yet in his job, he was doing extraordinary things."

Strange, 25, of Virginia Beach, Va., was among 30 U.S. service members killed early Saturday in the crash of a CH-47 Chinook helicopter in eastern Afghanistan, according to a statement from the International Security Assistance Force Joint Command. The coalition said a civilian interpreter and seven Afghan commandos also perished in the crash - the single deadliest encounter for U.S. troops since the war began soon after the Sept. 11, 2001, attacks.

The coalition provided few details about the crash, but U.S. officials told the Associated Press the Chinook was shot down during a mission to aid Army Rangers who had come under fire. Most of the troops who died were members of the elite SEALs, another of the special-operations forces that are increasingly carrying the war's burden.

Relatives said they knew little about Strange's duties as a petty officer first class with the SEALs, and had been asked not to discuss any details. But they spoke proudly about Strange's dedication to his unit and his country.

Charles W. Strange 3d said his older brother had talked about joining the military after 9/11 and had decided to join the Navy during his senior year. He began boot camp in August 2004, two months after graduating from Northeast Catholic High School.

"He wanted to get involved and go do something greater than himself," his brother said.

Strange fell in love with a fellow Navy recruit, Breanna Hostetler, during his first tour of duty when they were stationed together in Florida and Hawaii. When their enlistments were up, Hostetler left the military. She has been studying to become a psychologist, O'Brien said. But Strange was recruited by the SEALs and decided to re-up.

"He loved the physical aspect of it, the training," his brother said.

O'Brien added: "He was very proud of what he did - he loved the challenge. And he believed what he was doing was for the country."

Strange's father, Charles W. Strange Jr., said his son was a Navy triathlon champion, putting him at the pinnacle of an already elite group. Even so, he said he was once foolish enough to challenge his son to a footrace during a trip to the Shore.

It didn't end well for the elder Strange, a dealer at Philadelphia's SugarHouse Casino. "I had to take a bus back," he said.

O'Brien said that given Strange's family roots, she sometimes expected him to wind up working in law enforcement, perhaps for the FBI. His mother, Betsy Strange, is a Philadelphia police officer with the 22d District. His grandfather and great-grandfather were also on the force.

But relatives weren't totally surprised when Strange announced plans to become a nurse; he even began preparing for it via online coursework.

"He was a loving, gentle person," said his grandmother Bernice Strange, who wore a dress Sunday that her grandson had bought for her while stationed in Hawaii.

Strange's last leave was around his June 6 birthday, which gave him a chance to dote on his new niece, Juliana, now 9 months old. He even insisted on taking the new mother, his younger sister Katelyn, shopping. "He spoiled her - he bought her everything," Katelyn said, crying.

O'Brien said she stayed in touch with her nephew via e-mail, and always asked, "You there yet?" whenever he returned to the war zone.

"He'd e-mail back and say, 'Yeah, I'm here. I'm OK,' " O'Brien said, also fighting back tears. "He'd say, 'Tell everybody I love them.' That's what he said the last time he wrote."

Contact staff writer Jeff Gelles at 215-854-2776 or jgelles@phillynews.com.