Three former gas workers and the island's gas company are going on trial over the deaths of 10 people in an explosion at Haut du Mont in December 2022.
This complex investigation, dubbed Operation Spire, has taken almost four years to come to trial.
It has in fact been two major probes, running in parallel - one by States of Jersey Police and the other by the Health and Safety Inspectorate.
Neil Armstrong, Lee Ward, and John Wright, who were employees of the gas supplier at the time of the fatal blast on Pier Road in St Helier, are charged with gross negligence manslaughter.
Island Energy is being prosecuted under the Health and Safety Law.
All the defendants deny the charges.
The trial begins this morning (7 September) and is expected to take up to 12 weeks.
After today's jury selection, the case will be heard in a new courtroom created at Jubilee Wharf.
Ten islanders, Peter Bowler (72), Billy Marsden (62), Derek Ellis (61), Sylvia Ellis (73), Ken Ralph (72), Jane Ralph (71) Romeu De Almeida (67), Louise De Almeida (64), Raymond Brown (71) and Kathy McGinness (73) were killed in the explosion at Haut du Mont on 10 December 2022 just before 4am.

Storm Austen: All you need to know
Haut Du Mont: Jury fails to reach verdict on third gas worker
Storm Austen: Government schools to close on Friday
Haut du Mont: Gas workers convicted of manslaughter
Campaign encourages potential child sex offenders to seek help
Electric car charger grant to end in December
Consultation launched on hate crime legislation
Plans for Fort Regent transformation fall behind