(CBS) –Private Aaron Toppen, 19 was part of a special operation in southern province of Zabul in Afghanistan when he and four others were killed, possibly by a U.S. air strike.

CBS 2’s Suzanne Le Mignot reports Toppen’s family says they don’t want the focus to be on how he died, but that Toppen was doing what he loved.

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In a statement, the Department of Defense says, “Investigators are looking into the likelihood that friendly fire was the cause.”

Afghan police say Taliban militants started an attack after NATO forces had completed a special operation. During the fighting, five American troops were killed, possibly by an airstrike.

The 19-year-old’s loved ones say he wasn’t a typical teen. He was very focused about his career and devoted to his family. He loved his girlfriend, fishing and being with his friends. He was the type of person that would do anything, for anyone.

Aaron’s mother Pam says her son Aaron always wanted to follow other family members and join the military.

“It is something since grade school he told me he wanted to do, so this was following his dream and I am proud of him that he followed his childhood dream. I just wish it wouldn’t have ended like it did,” she said.

This is the second loss for Toppen’s mother in just four months. On February 7, her husband died after battling a number of health problems. Toppen was granted grievance leave for his father’s death. Then on March 8 he headed to Afghanistan via Romania to be with his battalion.

His goal after his time in the Army was to dedicate his life to a career in law enforcement.

Not long before Aaron Toppen went on his last mission, he spoke with his 19-year-old friend Ryan Gleason, who lives in Frankfort, Illinois.

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They sometimes spoke every day. Sometimes, Gleason says, just two or three times a week, depending on Toppen’s schedule in Afghanistan. And that last conversation?

“I told him to go bang skulls, have fun and be safe.”

Gleason says Toppen was supposed to come back home in August or September.

“Me and him had lots of plans for the future, dude. We always talked about running a company together, like a private security company.

“And of course, whichever one of us had a kid first, the other one had to be the godfather.”

Gleason’s request: that we recognize all the men and women who “have paid the ultimate sacrifice in the great war on terror.”

At Mokena’s VFW hall Tuesday night they were lifting a few in the young man’s memory, including the Iraq-era vet who coached him in pee wee baseball.

“He was just the nicest kid, never had a bad word, he was warm and genuine,” said Andy Cash. “Always wanted to be United States Army.”

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Aaron Toppen played on that ball team the year they won the village championship.