Nigeria: 2 Presumed Dead After Chevron Rig Fire Chevron Corp. says it has ended its search for two workers who went missing in a fire on an offshore rig near Nigeria's coast. Chevron said in a statement Thursday it extends its condolences to the families of the missing persons. However, it did not declare them dead and declined to give more details. The American energy company says it has accounted for 152 workers who had been present on the gas rig and a nearby barge when the fire started Monday. It said two workers were treated for minor burns. Chevron said an investigation into the fire is ongoing and believes equipment failure may have caused it. Nigeria's state-run oil company blamed it on a build-up of gas pressure.