WATERTOWN, Wis. (AP) -- A 21-year-old Marine from Watertown has died in Iraq. The father of Cpl. Matthew Zindars said his son was killed Tuesday by a roadside bomb while on patrol in Ramadi. The Marine was on his second tour of duty in Iraq. He came home from his first tour last October and volunteered to go back in March. He was due back in the U.S. this October. His dad, Ken Zindars, said his son volunteered for a second tour because his friends were going back, and they needed help. Matthew Zindars was a two-year member of American Legion Post 189. He graduated from Watertown High School in 2004 and attended Trinity-St. Luke's Lutheran grade school. Ken Zindars said his son's unit performed security operations and cleared roadways of explosives. He said Matthew enlisted while in high school and was proud to be a Marine. Zindars describes his son as decent, dependable and unpretentious. "I cant believe this is happening," one friend wrote on Matthew's MySpace.com page. "I cant stop crying but it does put a smile on my face when i think of all our good times!" The Associated Press contributed to this report.