When mount vesuvius erupted in 79 ad, the roman city of pompeii was buried under a thick layer of volcanic material. for centuries, the fate of its inhabitants remained a mystery, with many believing they were crushed by falling rock. however, modern forensic science and 3d mri scanning have revealed the truth, showing that the victims were actually killed by a pyroclastic surge, a fast-moving, superheated cloud of gas and volcanic matter that suffocated them in their final moments.