The BP oil spill trial in New Orleans opened on Monday with a scathing attack on safety standards before the United States' worst environmental disaster.
A federal judge is determining how much BP and drilling rig owner Transocean Ltd, Halliburton Co and other subcontractors should pay for the Gulf of Mexico spill in 2010.
Prosecutors are determined to prove that gross negligence caused the explosion that killed 11 men and sank the Deepwater Horizon rig. More than four million barrels of crude flowed into the gulf for 87 days before the well was capped.
Jim Roy of the plaintiffs steering committee told the court that the top safety official responsible for the rig was not even minimally competent for the job.
Mr Roy said the official's training had consisted of a three day course and he had never actually been aboard the Deepwater Horizon.
The plaintiffs did not take part in an $US8.5 billion settlement last year.
BP is spending $US37 billion on cleanup, restoration, payouts, settlements and fines. That includes a $US4.5 billion in penalties and civil claims from the US Securities and Exchange Commission.
The company has sold $US38 billion in assets to help cover its costs.
