The image pair above shows a closeup of the same area before and after the debris flow. Initially, there was some confusion about what caused the catastrophe, but a group of remote sensing scientists have mined satellite data for clues to fill in the sequence of events. Months before the landslide, satellite images showed a crack opening on an ice-covered flank of Ronti, a 6,029-meter (19,780-foot) mountain peak. As the accelerating rock and ice raced through Ronti Gad and then Rishiganga River valley, it picked up glacial sediments and melted snow. All the materials mixed into a fast-moving slurry that overwhelmed the river and churned wildly as it rushed through the river valley.