Investigators still don't know what killed Michael Heney, but they now know it wasn't a fall that killed him.

Heney, 20, of Chesterfield, Mo., was at an Edwardsville house on New Year's Eve in the back yard when he suddenly fell forward and struck his head on the porch about 10 p.m., according to investigators.

Heney sustained a serious gash to the head when he fell. His friends tried to take him to an urgent care center in Glen Carbon, but it was closed. They then called 911, which alerted Glen Carbon paramedics.

When the ambulance arrived, Heney was unresponsive and CPR was being administered, investigators said. Heney was taken to Anderson Hospital in Maryville, where he was pronounced dead at 10:59 p.m.

The Madison County coroner's office performed an autopsy Wednesday that determined Heney did not die as a result of the fall. Although the fall did cause several injuries, including a broken nose, it was not responsible for his death, according to Coroner Steve Nonn.

The actual cause of death has not been determined, as officials are awaiting further test results, Nonn said.

Lt. Scott Evers of the Edwardsville Police Department said his agency is investigating the incident jointly with the coroner's office and could not release any further information.

Heney was a student at University of Missouri, a junior majoring in business. He was a member of Pi Kappa Phi, according to the Columbia Missourian.

Funeral arrangements are pending at Schrader Funeral Home in St. Louis.

Contact reporter Elizabeth Donald at edonald@bnd.com or 239-2501.