On 20 May 2012, pressure caused by the slow movement of the Apennines through the Po valley caused a magnitude-6 earthquake to shake the Emilia-Romagna region. The first quake was followed in successive days by hundreds of aftershocks, leaving 26 people dead, 20,000 homeless and many historic structures damaged. The epicentre was in the province of Modena, and although the town itself was largely unaffected, the surroundings fared less well; many of the dead were workers in warehouses and factories which had not been constructed to withstand serious seismic movement. An important contributor to the local economy – the production of grana padano and parmigiano-reggiano cheeses – was affected when storage facilities collapsed, causing an estimated €200 million-worth of damage. In total, it is thought that the earthquake damage will exceed €4 billion, and experts believe that the spate of earthquakes will continue for years to come.