Chicago police say a 22-year-old exchange student from Ireland has died two days after diving off a pier into Lake Michigan.

The Cook County Medical Examiner's office identified the man as Keith O'Reilly of Dublin, Ireland, who died Saturday at Northwestern Memorial Hospital.

The exchange student's death was ruled accidental and an autopsy found he died due to brain damage and spinal injuries. He had been in critical condition since the dive.

Chicago police say O'Reilly apparently dove into the water early Thursday along North Avenue beach. They say the water at the pier was shallow and that O'Reilly hit his head on rocks.

Police say O'Reilly was with friends at the time.