John Dyer of Evendale says his 19-year-old son, Lance Corporal Christopher Dyer, was to start college in January as part of Ohio State's honors program. Dyer says his son had enjoyed his physics classes at Princeton High School but was thinking of studying business in college. Dyer was killed yesterday in a roadside bomb explosion in western Iraq. He was a member of the Lima Company, Third Battalion, 25th Marines. Nine of the 14 killed in the attack yesterday were from that company. John Dyer says his wife, Kathy, was in North Carolina with their 17-year-old twin daughters when Marines rang his doorbell at 3:15 yesterday afternoon to tell him of his son's death. Dyer says he hard about the attack yesterday morning and his worst fear was confirmed when he caught a glimps of a Marine uniform through his front door.