\r\nA photo from the scene shows the drawbar between two coaches had disconnected, with only the air hoses remaining intact. The cause of the drawbar separation appears to have been failure of a connecting pin bolt, a device similar to that of a coupler knuckle pin.Amtrak says there were 52 passengers on the train, and there were no reported injuries. \u201cWe are currently investigating the cause of the car separation, inspecting every Acela trainset, and taking any necessary actions to prevent a reoccurrence,\u201d says Mr Jason Abrams, an Amtrak spokesman.\r\n \r\nThis is not the first time that Amtrak\u2019s Acela Express trains have experienced problems with structural failures. \u201cThe equipment has an inherent design flaw in that it is too heavy, a consequence of having to meet stringent Federal Railroad Administration crashworthiness standards,\u201d noted an industry observer. \u201cIt is a largely European design that was adapted for North America. The equipment is now more than 20 years old and beginning to show even more signs of ageing, much more so than, say, the Amfleet equipment that has been in service for almost 40 years and despite its advanced age continues to provide good service.\u201d\r\nThe Acela Express\u2019s weight-related problems have included excessive wheel wear, cracked carbody yaw damper brackets, disintegrating inboard disc brake rotors, and now the drawbar separation.\r\nThe incident is the latest in a recent string of mishaps for Amtrak. On February 4, two crewmen died after the southbound Silver Star collided head on with a stationary CSX freight train on a loop in South Carolina. A few days earlier, a chartered train carrying Republican members of Congress to a retreat struck a waste truck at a level crossing in Virginia, killing a man inside the truck cab.\r\nOn December 18, three people were killed and more than 70 were injured when an Amtrak Cascades train derailed while traversing a curve leading into a bridge over the Interstate 5 highway southwest of Tacoma, Washington, sending a locomotive and coaches crashing onto the highway below. The National Transportation Safety Board (NTSB), in preliminary findings based upon event recorder data, identified the cause of the accident as an over-speed condition.