A major earthquake (the great Tohoku earthquake, Mw = 9, local peak ground acceleration = 0,96 m/s²) striked at 2:46 pm an electronic components plant (silicon wafers). The production building , built according to the latest seismic standards 10 years before and able to withstand accelerations of 4m / s ², suffered significant structural damage aggravated by aftershocks 1 month after : cracked walls, collapsed suspended ceilings and overhead cable trays, displaced or fallen high-precision machinery despite their ground anchors. Clean room was unusable and holes in its roof was source of non-sterile air contamination. The electrical station supplying the building is severely damaged. For two months, more than 2500 people (employees, suppliers, customers and subcontractors) worked for rehabilitating the plant whose production is strategic for the national industry, as it provides a quarter of the world production of specific automotive waffers. The plant was back to full production six months later. The amount of damage is estimated at 431 million of euros and the cost of production losses and restructuring at 64 million of euros.