A 20-year-old Hawai'i-based Marine was killed in Helmand province in Afghanistan on Friday, a reminder of the deadly day-to-day efforts of U.S. forces in the southern part of the country.

Lance Cpl. Curtis M. Swenson of Rochester, Minn., was killed "while supporting combat operations in Helmand province," the Pentagon said yesterday.

Swenson was part of the 1st Battalion, 3rd Marine Regiment, from Marine Corps Base Hawai'i at Kāne'ohe Bay, and was a mortarman with Weapons Company. The 1,000 Marines and sailors of the 1st Battalion have been in and around Nawa in central Helmand since November. Five from their ranks have been killed.

His sister, Emily Swenson, created a Facebook page for her brother.

"You were loved and lost, but never forgotten, I will miss you brother, always always in my heart," his sister wrote.

More than 350 people had left condolence notes as of yesterday evening.

"Oh Katie Rae, I love you so much and I am so sorry this happened ," Shiann Oxley said to the Marine's wife. "I never got to meet him but it looks like you married a wonderful, loving, and brave man. I want to send my love and prayers to you and to Curtis's family. He will always be with you and never forgotten."

The Rev. Norman Wahl, senior pastor of Bethel Lutheran Church in Rochester, Minn., said Swenson was very active in the church, the Minneapolis-St. Paul Star Tribune reported.

"He was heavily involved in the youth program," the newspaper cited Wahl as saying. Wahl said Swenson had participated in church trips to California and Montana, and youth ski trips to Duluth, Minn.

Cody Wright said on the Facebook page that a memorial service would be held for Swenson on Saturday in Afghanistan.

"I was put in charge of Curtis as soon as he hit the fleet," Wright said. "I trained him to be a mortarman and was ... with him for his first deployment. He was a good man and a damn fine Marine. All of Weapons Company will be honoring him."

Marine Corps Base Hawai'i said Swenson enlisted in the Marine Corps in June 2007. He had previously deployed to Iraq in August 2008.

His decorations include the National Defense Service Medal, the Global War on Terrorism Service Medal, Iraqi Campaign Medal and the NATO-International Security Assistance Force Afghanistan Medal.

Two Marines out of Camp LeJeune, N.C., were killed Thursday in Helmand province, and a British soldier was killed on Sunday in the province by a roadside bomb.