A colossal volcano in Alaska is likely to erupt soon, scientists warn. Mount Spurr, an 11,000-foot-tall volcano on the Cook Inlet about 75 miles from Anchorage, has a 50-50 chance of spewing out hot magma and ash that could be toxic for humans to breathe,

An uptick in seismic activity at Mount Spurr, a massive volcano in Alaska, has scientists watching closely for signs of an imminent eruption. They say there's a 50-50 chance it could blow soon.