ST. LOUIS (AP) — Beneath the surface of a St. Louis-area landfill lurk two things that should never meet: a slow-burning fire and a cache of Cold War-era nuclear waste, separated by no more than 1,200 feet. Government officials have quietly adopted an emergency plan in case the smoldering embers ever reach the waste, a potentially "catastrophic event" that could send up a plume of radioactive smoke over a densely populated area near the city's main airport.