we have the tick tok. we know what happened. they have the person detained. they'll try to figure out what went on. again what we do know is this man had a large knife. he started to attack people on the bridge. we know that we've seen social media video. passersby then jump on him. there is a scuffle on the bridge there before police arrive. they arrive on the scene quickly. pull the passersby off and shots are fired at the man. we also know he doesn't die at that point. we see him move in later videos. so he has been detained at this point. again the motive is one thing we don't know about yet and have to be cautious. usually the operation for a terror attack we often see them using cars to start off with. london has suffered a severe hike in knife crime recently.