By Nicola Nosengo of Nature magazine

Six Italian seismologists and one government official will be tried for the manslaughter of those who died in the earthquake that struck the city of L'Aquila on 6 April 2009.

The seven were on a committee that had been tasked with assessing the risk associated with recent increases in seismic activity in the area. Following a committee meeting just a week before the quake, some members of the group assured the public that they were in no danger.

In the aftermath of the quake, which killed 309 people, many citizens said that these reassurances were the reason they did not take precautionary measures, such as leaving their homes. As a consequence, the public prosecutor of L'Aquila pressed manslaughter charges against all the participants in the meeting, on the grounds that they had falsely reassured the public (see Italy puts seismology in the dock). After several delays, the public prosecutor Fabio Picuti and the defendants' lawyers appeared this week before Giuseppe Gargarella, the judge for preliminary hearings, who had to decide whether to dismiss the case or proceed with a trial.

During the hearing, the prosecutor called the committee's risk assessment "superficial and generic", resulting in "incomplete, imprecise and contradictory public information". Responding to the thousands of scientists who had signed a letter of support for the defendants, the prosecutor acknowledged that the committee members had no way of predicting the earthquake, but he accused them of translating their scientific uncertainty into an overly optimistic message.

More specifically, the accusation focuses on a statement made at a press conference on 31 March 2009 by Bernardo De Bernardinis, who was then deputy technical head of Italy's Civil Protection Agency and is now president of the Institute for Environmental Protection and Research in Rome. "The scientific community tells me there is no danger," he said, "because there is an ongoing discharge of energy. The situation looks favorable".

That statement does not appear in the minutes of the meeting that preceded the press conference, and it was later criticized as scientifically unfounded by seismologists - including Enzo Boschi, president of the National Institute of Geophysics and Vulcanology, who is also one of the accused. Much of the trial is likely to revolve around the origin and impact of De Bernardinis's statement.

The defendants' lawyers have tried to differentiate between their clients' respective positions, in some cases implicitly blaming each other's clients. Boschi and the other scientists stated that informing the public was the sole responsibility of civil-protection officials, and that they cannot be charged over what was said in their absence. De Bernardinis's advocate, on the other hand, said that his client merely summarized what the scientists had told him, and that the evaluation of the situation as "favorable" had come from them. According to the prosecutor, the fact that none of the other committee members felt the need to immediately correct De Bernardinis's statement makes them all equally culpable.

At the end of the hearing, the judge decided that the trial will begin on 20 September. Boschi has said in interviews that he feels "devastated" by the ruling, and that he expected the case to be dismissed. He notes that there are hundreds of seismic shocks every year in Italy: "If we were to alert the population every time we would probably be indicted for unjustified alarm," he said. He also denied ever having reassured the population or downplayed the risk. "There is no document whatsoever proving I did something like that," he says, adding that the main cause of the tragedy was the poor building standards in the area. "I hope the trial will better clarify what role the seismologists really had in this story".

The other defendants have declined to comment. If found guilty, they could face jail sentences of up to 12 years.

Vincenzo Vittorini, a physician in L'Aquila whose wife and daughter were killed in the earthquake and who is now president of the local victims' association '309 Martiri' (309 Martyrs), hopes the trial will lead to a thorough investigation into what went wrong in those days. "Nobody here wants to put science in the dock," he says. "We all know that the earthquake could not be predicted, and that evacuation was not an option. All we wanted was clearer information on risks in order to make our choices".

He says that the committee had precious information that was not passed on to citizens, for example on which buildings were most likely to collapse in the event of a strong earthquake. Vittorini thinks that those charged are not the only ones to blame, and that further investigations might eventually place greater responsibilities on politicians at the local and national level.

This article is reproduced with permission from the magazine Nature. The article was first published on May 26, 2011.