An enormous reservoir of magma has been discovered beneath Yellowstone National Park in Utah. How enormous? The Week describes it as enough to fill the Grand Canyon "almost 14 times."
But don't go packing your emergency rations yet. Scientists report that the likelihood of the long-known supervolcano releasing its tides of destruction are about 1 is 700,00 for any given year. According to the Insurance Information Institute, that's about the same as dying by "falling on [or] from [a] ladder or scaffolding."
For all the times I've breached OSHA regulations on the use of ladders, let me tell you: you've got nothin' to worry about. Besides which, if it did go off, there's hardly anywhere on the planet you could go to get away from it.