Here's a story from one of Kerry's emails:
As I walk to work every morning I pass a little bridge that is called "Tuna bridge." There is a small sign that explains the curious title. Back in 2003 before the base was built up there was no bridge and this area was a crossing site for a small stream. One day as an Infantry unit was preparing to cross the site their lieutenant saw a small metal ring that was sticking out of the mud. Instantly halting his platoon both he and his Platoon Sergeant stared at the ring with concern. Afghanistan was full of land mines, and this most likely was the handle on a land mine. Thinking quickly, the entire unit halted and the EOD was called in. Engineer assets were also called in and a small bulldozer was employed to clear away the area. After several hours of tedious and careful work (after all...we are talking about a land mine!) the EOD personnel slowly and cautiously pulled out the metal ring. The mud and earth slowly gave way...and a small can of tuna emerged from the muck. Thus the name Tuna Bridge.