2009 L'Aquila earthquake region saw dozens of significant aftershocks following the main earthquake. The strongest, which hit at 19:47 CEST on 7 April, measured magnitude 5.3 and caused further damage. According to the Italian National Geophysics Institute director Boschi, the aftershock epicentres migrated south-east, thus lessening the risk of further major shocks near populated areas. Aftershocks caused safety problems for rescue crews searching for injured victims trapped in precarious structures in the historic center of L'Aquila, a medieval city. Using cranes and backhoes to remove loose bricks and broken timbers, the crews were aware that even a small aftershock could have triggered the
2009 L'Aquila earthquake of European Centre for Earthquake Engineering; Claudio Eva, physicist; Mauro Dolce, director of the Civil Protection Agency's earthquake risk office; Bernardo De Bernardinis, former vice-president of Civil Protection Agency's technical department. Boschi had called a major earthquake "unlikely", while not entirely excluding the possibility. De Bernardinis had informed the public that there was "no danger". The prosecutors cited a scientific opinion that the low-level tremors ahead of 6 April quake were typical of the seismic activity preceding major convulsions, but the defendants had classified them as a "normal geological phenomenon". They were criticised in court for being "falsely reassuring" and