Charges may soon be upgraded to murder against a Waterloo man after the death of his four-month-old son. Skylar Tate died of his injuries at University Hospitals in Iowa City Wednesday night. An autopsy will be performed later today in Des Moines to determine the exact cause of death. He was found unresponsive at his home Tuesday night, with injuries, including the swelling of the brain. His father, 21-year old James Tate, was arrested on child endangerment charges and remains held in the Black Hawk County Jail. No other information is being made available by Waterloo police at this time.