USMC Vietnam 1969 -- I was to ride "shotgun security" on a fuel truck going to the rear to refill. My buddy asked if he could go on the truck in my place because he wanted to pick up something, so I said sure and got off the truck and watched him jump in in my place. A short distance down the dirt road from where we were the truck hit an anti-tank mine and the truck was destroyed. My buddy and the driver were both killed. It just wasn't my turn that day.