NEW ORLEANS (AP) — A federal judge conducting a trial to assign fault for the nation’s worst offshore oil spill dismissed claims Wednesday against a BP contractor and the company that made a key safety device on the drilling rig that exploded in the Gulf of Mexico, triggering the disaster.

After plaintiffs’ attorneys rested their case Wednesday, U.S. District Judge Carl Barbier ruled there was no evidence that BP’s drilling fluids contractor M-I LLC made any decision that led to the blowout of BP’s Macondo well. Barbier dismissed all claims against M-I on the 15th day of the trial.