SWANTON, Vt. – A Marine known in his hometown for his manners and his smile has become the third Vermont resident to die in Afghanistan this year.

Marine Lance Cpl. Anthony Rosa, 20, of Swanton was killed Thursday while supporting combat operations in Afghanistan’s Helmand province, the Department of Defense said. He was a 2008 graduate of Missisquoi Valley Union High School and was assigned to a battalion based at Camp Lejeune in North Carolina.

Bill Rowell, a close friend of Rosa’s family, said Rosa went by the name “Chuckie,” a nickname given to him by his grandfather.

“The kid grew up on my knee,” he told the Burlington Free Press.

Rowell said Rosa was an excellent golfer, an avid fisherman and a good student.

“He was a perfectly mannered gentleman, and strikingly so,” he said. “And good looking. If he smiled at you, you were done. He wasn’t perfect, but he came closer to it than most.”

Philip Ste. Marie said Rosa worked at his convenience store in Swanton during high school. While other teenagers called their boss by his first name, Rosa always said, “Yes, sir.”

“He was very polite, a very popular kid in high school,” he said.

In high school, Rosa was voted the student with the best smile and laugh.

Members of the state’s congressional delegation offered their sympathies to Rosa’s family, which includes his mother and stepfather, his father, and two sisters.

“In a small state like ours, we Vermonters are all hit hard by this news,” said Democratic Sen. Patrick Leahy.

Sen. Bernie Sanders, an independent, said, “Another Vermonter has paid the ultimate sacrifice in our country’s longest war. Our thoughts and prayers are with his family and friends here in Vermont and with the brave men and women he served with in Afghanistan.”

Democratic Rep. Peter Welch said that by all accounts, Rosa loved life, Vermont and his country.

“His loss is a heartbreaking blow to the town of Swanton, to the state of Vermont and, most devastatingly, to his family,” he said.

Two other soldiers from Vermont have died in Afghanistan this year, both Vermont Army National Guardsmen. Spc. Ryan Grady of West Burke died July 2.

Spc. Tristan Southworth of Walden died Aug. 22.

Another Vermont National Guardsman, Sgt. Steven Deluzio of South Glastonbury, Conn., also was killed Aug. 22.