Choppers clattering in the sky above, bloodstained students watch in shock as blaring ambulances screech into the schoolyard, disgorging paramedics with medicine packs and gurneys. At least that's what it looked like, as one California school put on a graphic display of what will happen when -- not if -- the Big One hits this earthquake-prone western US state. Nearly eight million Californians were signed up for Thursday's drill, the most ever, after 6.9 million took part last year. Photo courtesy: AFP.