Philadelphia police are investigating a scary attack in Pennypack Park.
A woman says she was yanked off her bike while riding along the 3000 block of Rhawn Street in Holmesburg.
The 55-year old victim told police she was grabbed from behind and forced off her bike.
The unidentified attacker threw her over a guardrail into the park.
According to investigators, he cut off air to her nose and mouth until she was unconscious. When the woman came to, she was naked wearing only her shoes. She does not remember a sexual assault taking place.
The attacker got away with the woman's blue mountain bike and several other items, including her clothes.
This is not the first attack in the area. Last August, a naked man grabbed a woman from behind and tried to sexually assault her.
Authorities believe the same man also attacked two other women one in May 2010 and the other in July 2009.