(AP) — An autopsy has failed to pinpoint a cause of death for a 6-month-old girl whose father says he forgot her, leaving her in his car for six hours with the windows rolled up in a suburban Portland parking lot last October. While the autopsy wasn't conclusive, Dr. Clifford Nelson of the Oregon state medical examiner's office said it's possible she died in her sleep before the car heated up. A search warrant affidavit unsealed Tuesday suggested police suspected heat was involved in the death. The affidavit quotes Intel worker Joshua Freier, 38, as saying he was taking his daughter to day care on Oct.