The cause of the accident was reportedly due to a broken track that caused a derailment. Officials are not sure yet if the train collided head-on or if the derailed train was hit from behind.
Often train collision, such as the Los Angeles Metrolink train crash in September 2008, are due to human error. Even though in this case it appears that a broken track was to blame, the escalation of this event into a catastrophe may have been preventable.
This is not the first time Washington Metro trains have been involved in accidents. With the exception of one incident in 1996, which was attributed to the inability of train operators to override automated breaking systems, tragic accidents in 1982, 2004, 2005 and 2006 were in part attributed to human error.
Hopefully this event can be used as an awaking for transit systems to move to more advanced train control system, perhaps fully automated systems. Derailments may not be entirely preventable, but many collisions are. Perhaps we can use this tragic accident as a catalyst for upgrades to our transit systems in the United States. As many systems, such as BART in the San Francisco Bay Area, are due to fleet replacements this may be the opportune time to not only increase safety, but lower operating costs.
Link to BBC Video of the crash.
*NOTE: the image pictured above is from a 2004 incident.