Today's "Planet Earth Report" --Hawaii's Kilauea, Longest-Erupting Volcano, Next to Eject 12-Ton Boulders

"If an explosion happens, there's a risk at all scales," said Donald Swanson, a USGS volcanologist. "If you're near the crater, within half a mile, you could be subject to ballistic blocks weighing as much as 10 or 12 tons."...