In an open letter displayed near her father's flag-draped casket, Christine Davis wrote she is "the proudest daughter in the world."

Her dad, Master Sgt. Jefferson "Donnie" Davis, was one of three Green Berets killed earlier this month in Afghanistan.

More than two dozen of Davis' fellow Special Forces soldiers joined some 400 mourners at his funeral at Elizabethton High School, where Davis graduated in 1981. Burial followed at Happy Valley Memorial Park.

"There are no words to express how I feel right now," Christine, 14, wrote. "Sadness and anger mostly fill my mind. But I am also the proudest daughter in the world. God couldn't have ever given me a better father."

Davis, 39, known as "Jeff" or "J.D." to his friends in the military and "Donnie" to his family in the tiny neighboring town of Watauga where he grew up, was killed Dec. 5 by an errant bomb.

Also killed were Staff Sgt. Brian Cody Prosser, 28, of Frazier Park, Calif., and Sgt. 1st Class Daniel Petithory, 32, of Cheshire, Mass. All were stationed at Fort Campbell, Ky., near Clarksville.

Twenty other soldiers were injured and six Afghan fighters were killed in the incident.

Tuesday's services concluded with taps and "The Ballad of the Green Beret" played by a lone bagpiper.

In addition to family and friends, the funeral was attended by members of the Rolling Thunder Vietnam veterans motorcycle club, some wearing black leather chaps, and local elected officials.

"It hurts," Maj. Gen. Geoffrey C. Lambert, the Green Berets' commander, said after the service. "I hate losing such fine young men. But it was for a good purpose."

Lambert presented Davis' Korean-born widow Mi Kyong Davis of Clarksville and their children Christina and Jessie, 10, with a posthumous Silver Star for valor, a Purple Heart and a Combat Infantry Badge.

The security of the nation was assured "as long as we have husbands, sons and warriors like J.D. Davis," he quietly told them.

David Beireis, a retired Special Forces member, recalled becoming a Green Beret 12 years ago this month with Davis, "a scrawny corporal but just as capable as any one of them."

"He was the kind of Special Forces soldier anyone could be proud of," Beireis said.

Master Sgt. Monty Flanigan, who served in the same battalion with Davis and spoke at the funeral, brought a dozen letters of condolence from people around the country that had been mailed to Jefferson Davis, 81, of Clarksville.

"It just amazed me. The spirit of the people of our nation to do that," Flanigan said.

"He was a good man. We lost a lot," Flanigan said of Davis. "He is as good as there is and I would say that if he was standing right here. I'd say the same thing."

Davis was buried about five miles from his small hometown. He was eligible for burial in Arlington National Cemetery, but his wife wanted him buried in Carter County to be close to his family.

Davis, voted "most sweetest" by his graduating class at Elizabethton High School, loved motorcycle riding, fishing and spending time with his family.

He left northeast Tennessee years ago, attending Lees McRae College in North Carolina on a football scholarship and later East Tennessee State University in Johnson City where he studied nursing.

He joined the Army in 1983 and began a Special Forces career as a medic. It took him to many of the world's hot spots, from Desert Storm to Africa, over the last decade and a half.

The Associated Press contributed to this report.