that once his concussion sub sides, the concussion that he suffered in that crash, that his memory may return. fredricka? do we know when service is going to resume? we re talking about the weekend, and you know thousands of people rely on the amtrak northeast corridor every day. but particularly on weekends. when people you know are returning from work or getting ready for the work week. yeah now we know they are hard at work trying to repair the railroad. amtrak authorities had said that service has been suspended along the new york/philadelphia route through monday. there is a possibility that some sort of service may return on tuesday. all right. erin mclaughlin. thanks so much keep us posted from philadelphia. let s talk more about the amtrak investigation, joining me now, mary ski a of ao a cnn transportation specialist and a former inspector general of the national transportation department and richard viehl is