There isn’t a corner of the United States where students haven’t pondered the possibility of a lunatic with a gun barging into their classroom. So when police surrounded the West Marin School last week, the kids knew what to do.
Students in the sixth-grade Spanish class hid behind a white board and crouched beneath tables. Principal Beth Nolan’s words were fresh in their ears: “We’re on lockdown,” she announced over the P.A. system at around…