Authorities say a determination of the cause of death of the 21-year-old grandson of Texas oil tycoon T. Boone Pickens could take two to four weeks.

Linda Anderson, a spokeswoman for the Tarrant County medical examiner, says an autopsy is being conducted Wednesday on the body of Thomas Boone Pickens IV.

The grandson, known as Ty, was enrolled as a junior at Texas Christian University. Police were dispatched after receiving a report of a dead person at an off-campus location Tuesday morning. Police said Pickens was transported to a hospital, where he was pronounced dead.

The elder Pickens made much of his fortune in oil drilling but has since become an advocate for alternative energy.