This chapter describes a rockfall that occurred at Corno Grande, the highest peak in the Apennines, in Italy on August 22, 2006. A limestone block with an estimated volume of about 30,000 m3 fell from the sub-vertical northeast slope of Corno Grande. Although relatively small, the rockfall covered a large area (ca. 35,000 m2) with debris and generated a giant abrasive dust cloud that affected an area of ca. 110,000 m2 at the base of the slope. The dust cloud extended 3 km from the source slope and reached the village of Casale San Nicola. The A24 motorway was temporarily closed due to limited visibility. The rockfall was recorded by a seismometer array located in the nearby Gran Sasso underground laboratories (LNGS – Laboratori Nazionali del Gran Sasso). We processed the seismic data to assess the evolution of the rockfall in terms of mean velocity, impacts, and energy dissipation. The field surveys and data derived from the seismometer array allowed us to constrain the kinematic evolution of the failure. At least three debris impacts can be seen in the available data; they triggered an air blast and the dust cloud.