The eruption was heard hundreds of miles away, but some of those who survived the eruption declared that the landslide and pyroclastic flows were silent as they raced down the mountain. Kran Kilpatrick, an employee of the United States Forest Service, recalled, "There was no sound to it, not a sound. It was like a silent movie and we were all in it." The reason for this discrepancy is a "quiet zone", created as a result of the motion and temperature of air and, to a lesser extent, upon local topography.