Marine Lance Cpl. Posivio was assigned to 1st Battalion, 1st Marine Regiment, 1st Marine Division, I Marine Expeditionary Force, Camp Pendleton, Calif. Posivio was killed while a passenger in a high mobility multipurpose vehicle that was hit by an improvised explosive device while conducting combat operations against enemy forces. Robert attended and graduated from Martin County West High School in 2002. While in high school, Robbie was active in football, wrestling, track, band and choir and Future Farmers of America. For his high school graduation present he wanted and received a fly-in fishing trip to Canada. He enlisted in the United States Marines right out of high school and served three tours of duty in Iraq. On April 13, Robbie was injured in a mortar attack when his unit came under fire in Al Anbar for which he received a Purple Heart – the Purple Heart arrived at his family's home the day after they were informed of his death. Then about three weeks after that attack, he suffered a severe concussion and shrapnel wounds in another attack. One of the Marines killed in that attack was Lance Cpl Stephen Perez, who died while saving Posivio's life. There is a photo that shows Posivio kneeling before a memorial made from a helmet resting on a rifle with a set of identification tags and a pair of combat boots during a memorial service for Perez on April 28 at Camp Fallujah, Iraq. He was sent back into the field on April 30 and was due to be honorably discharged on July 28. Robbie took great pride in serving his country. Whenever he would return home on leave and attend public gatherings or make speeches, he was always in full uniform. In his spare time, he loved hunting, fishing, spearing, Harley Davidson motorcycles, snowmobiling and spending time with his family and friends. He also spent time driving his new Chevy truck and playing with his Springer spaniel dog, "Spot". Robbie's plans for the future involved taking over the family farm.

NOTE: His death was a particularly hard blow to his family because his younger brother, Daniel, 19, was killed in a car accident July 27, 2004 while on leave from the Navy.