No charges will be filed for an incident that left a 16-year-old brain tumor patient unconscious at HP Pavilion during a game between the Sharks and Canucks earlier this season.Canucks fans Maggie Herger, 16, was hit on the back of the head from behind and fell unconscious during the December 28 game. She was transported to a local hospital via ambulance following the injury and diagnosed with a mild concussion.According to a report in the San Jose Mercury News, Herger's sister told police that she had overheard the woman sitting behind her Maggie tell an usher that she had brought her hands down on the girl's head accidentally following a Sharks goal. Santa Clara County assistant district attorney David Howe released a statement:"No fan should worry about their safety at a sporting event. However, the evidence is insufficient to establish who committed the act that resulted in the teen's injury and whether the attack was intentional or accidental."The Mercury News is also reporting that Herger's headaches have subsided since the incident.