The grief-stricken mother of a U.S. soldier slain in Iraq has died of unknown causes, only hours after identifying her son's body.

Friends of Karen Unruh-Wahrer say the 45-year-old Tucson, Arizona woman suffered intense grief and could not stop crying after being told that her son, Robert, was killed by enemy fire in Baghdad last week. The 25-year-old combat engineer had been in Iraq only one month when killed.

Last Thursday, several days after learning of her son's death, Mrs. Unruh-Warner went to the hospital for chest pains. She later felt better, but died Saturday night in her kitchen after seeing her son's body that afternoon.

An autopsy has been conducted, but results have not been released.

The mother's body will accompany her son's in a funeral procession Friday to the cemetery where he is to be buried.