FILE - In this Wednesday, April 21, 2010 file photo, oil can be seen in the Gulf of Mexico, more than 50 miles southeast of Venice on Louisiana's tip, as a large plume of smoke rises from fires on BP's Deepwater Horizon offshore oil rig. An April 20, 2010 explosion at the offshore platform killed 11 men, and the subsequent leak released an estimated 172 million gallons of petroleum into the gulf. The Gulf oil spill settlement trial has started in New Orleans, Monday, Feb. 25, 2013. U.S. District Judge Carl Barbier is scheduled to hear several hours of opening statements Monday by lawyers for the companies, federal and state governments and others who sued over the disaster. Barbier is hearing the case without a jury. The trial is designed to identify the causes of BP's well blowout and assign percentages of fault to the companies. (AP Photo/Gerald Herbert, File)
NEW ORLEANS (AP) — The owner of the drilling rig that exploded in the Gulf of Mexico in 2010 has started to present its defense at a trial designed to determine the causes of the deadly disaster and assign fault to the companies involved.
Transocean Ltd. called its first witness Monday on the 13th day of the trial.
A federal judge already has heard testimony by more than a dozen witnesses called by the Justice Department and attorneys for Gulf Coast businesses and residents who claim the spill cost them money.
The plaintiffs' lawyers still expect to call another witness to the stand this week, an employee of cement contractor Halliburton.
Halliburton and Macondo well owner BP PLC also will call their own witnesses after Transocean finishes presenting its case.