A judge in the Italian city of L'Aquila is reviewing evidence against six scientists and a government official.
They are accused of failing to give adequate warning of a 2009 earthquake that devastated the city.
The quake killed 308 people, injured hundreds and made over 60,000 people homeless.
The geologists and vulcanologists were members of a natural disasters committee that held an emergency meeting in L' Aquila, just six days before the earthquake struck.
Prosecutors argued that the commission failed to warn of the danger - and instead said the tremors were not a cause for concern.
The manslaughter trial has proved immensely controversial, with the international scientific community claiming earthquakes cannot be predicted.
If found guilty, the seven could face up to four years in prison.
