Clarksville, TN – The promise of low prices at Black Friday shopping led to injury in Clarksville, Tennessee, early today. Shoppers crowded outside a Clarksville Toys-R-Us that was set to open at midnight. Police reports say when the doors opened momentarily, the crowd shoved forward, knocking 32-year-old Clarskville resident Amy Serna to the ground. Several people trampled Serna, causing injury to her knee. She was transported to Gateway Medical Center for care. Police have charged no specific suspects for the assault.