At approximately 7:00 pm, protesters began assembling on the Backwater Bridge.  Some of the protesters were equipped with shields and gas masks and they started a fire on the south end of the bridge.  The protesters also erected teepee poles on the bridge. At approximately 7:30 pm, law enforcement officers entered the bridge and moved the protesters back and while on the bridge dismantled and removed the teepee poles.At approximately 8:00 pm, the protesters again began assembling on the bridge.  The number of protesters continually increased over the next two hours and the protesters were throwing a variety of objects at the law enforcement officers present at the barricade on the north end of the bridge.  The objects included burning emergency flares, ice chunks, and frozen water bottles. At 10:20 pm, the number of protesters on the bridge was estimated at approximately 175.  The situation continued past midnight.