The ntsb lead investigator and joyce joins us from philadelphia with the latest. Suzanne it remains a very active scene here in philadelphia. The ntsb is back at it, looking at video from the forwardfacing camera on that train. They will be further analyzing information provided by the event data recorder. They will also be interviewing passengers. We want to tell you, the two railcars remain at the derailment site today. Investigators will be doing a laser scanning of those cars before they are released to amtrak are the main focus continues to be the speed the train was traveling, which was in excess of 100 miles per hour. Why was that train traveling so fast . Authorities are looking into the role that positive train controls could have had here tuesday night. The train control is designed to provide an additional layer of redundancy so that if some of the makes a mistake, the system will intervene and not allow a catastrophic accident to occur. Suzanne 16 people remain hospitalized