The trial opens today into the blast at a chemicals factory near Toulouse in southern France which killed 31 people, eight years ago.A concert hall has been rented for the event with hundreds of plaintiffs expected to testify about the impact of the explosion on their lives. France’s biggest company, Total, which owned the plant, and a former factory manager face charges of manslaughter and property destruction. Some 31 people were killed and 2,500 were seriously wounded in the explosion at the AZF factory. It happened just 10 days after the September 11 attacks, raising fears of a terrorist assault. But prosecutors found the blast was the result of an accidental chemicals mix. The accused deny the allegations. Victims and their families have already received two billion euros in compensation from Total. Serge Biechlin, the ex-factory manager, faces up to three years in jail. The trial is expected to last three to four months.