Margarito (or "Chico," as we all knew him) was shot by 'friendly' ARVN troops while driving a Jeep at the Moc Hoa airfield in Kien Tuong Province. He was trying to stop a fight between South Vietnamese (ARVN) troops and the local "Mike Force" company, who were mostly Cambodians.
I served with him at B41, 5th Special Forces Group (Airborne) from the time he started his tour in April 1968 until he was killed. He was a good man, a good friend.
