FALMOUTH, Maine (NEWS CENTER) -- We're learning more tonight about Senior Chief Special Warfare Operator Kyle Milliken, the Navy SEAL from Falmouth, killed in combat in Somalia.

Several groups have expressed their gratitude for Milliken's service -- from Maine's congressional delegation to Milliken's high school.

But those who knew him before his time in the service say Milliken had special qualities that made him the right person to join one of the most elite team's in the US military.

Determination, mental toughness, and perseverance despite all odds - those qualities are what helped Milliken become a member of SEAL Team Six - one of the most highly trained elite forces in the US military.

Those who knew Kyle Milliken say his work ethic always made him stand out - as a good athlete, and then a good Navy SEAL.

NEWS CENTER spoke with his track coach at the University of Connecticut, Greg Roy. He says Milliken wasn't the most naturally gifted runner on his team - but his work ethic separated him from others.

Roy says when he found out Milliken became a NAVY Seal after graduation, he was surprised at first - but then realized that the same qualities he saw at track practice would make the perfect NAVY Seal.

"If you're in Kyle Milliken's shoes, you better be a lot of things," he said. "You better be 100% committed, you've got to be tough as nails, you've got to have the ability to persevere, you have to have the ability to believe in yourself. Kyle Milliken made this team better when he was there and when he was a teammate."

Fox News contributor and military analyst Colonel David Hunt says these qualities embodied by Kyle Milliken are essential for work as a Navy SEAL.

He says the graduation rate for the NAVY Seal program is under twenty percent - and only a tiny fraction of those people are considered for elite teams like SEAL team six.

"It's much more determination, and guts, and perseverance than it is physical," explained Colonel Hunt. "There aren't that many people who physically want to put up with it, but have what Kyle had - this determination the coach talks about. Shows up before practice, after practice, extra laps, in the weight room. That's what it takes to get just through the basics of Rangers, or Delta, or SEALs or special forces."