The construction of a large underground car park in the area between viale Sabotino and the walls of Spanish date visible near Porta Romana, made it necessary to undertake an open area rescue excavation. The zone corresponds to the strip of land between the fortified walls built in the second half of the 16th century (on the orders of the governor Ferrante Gonzaga in the name of Philip II of Spain) and the land outside the moat of the same walls. At only one metre further south of the line of the wall which for a long period constituted the boundary between city and countryside, a common grave 2.5 m wide and over 46 m long had been dug and probably very quickly refilled. There were at least 157 individuals whose skeletons were still articulated but in jumbled positions, often in a prone position (47 individuals) but also supine (74 individuals) and on their side (13 individuals). The remaining individuals were too fragmented to establish their position. Most of them were adults and only 14 individuals were identified as children or babies. The deceased were found in 16 distinct groups separated by dumps of rubble. The jumbled way in which they lie suggests that the bodies, without shrouds, were dumped directly from wagons into the pit. The haste to dispose of these bodies and their particular position inside the common grave suggests that death was caused by an epidemic, which in this period may be identifies as the plague. The presence of a “foppone” (a word from Lombard dialect meaning “great pit”) or emergency burial ground just outside the city limits conforms to the procedure documented in historic sources of the period.