The Johnson County coroner in Kansas reportedly said that Joshua Adams died after an accident on an oil rig led to blunt force trauma, though the exact cause could not be identified.

The rig was contracted by Basic Energy Services.

Meanwhile, a worker at Citgo Petroleum's refinery in Corpus Christi, Texas, was found unconscious late on Monday night. He was taken to hospital where he was pronounced dead.

An investigation into the incident was ongoing, a Citgo spokesman said.