The exact cause of the DC Metro crash is still unknown. Part of the cause could be faulty control circuits and authorities are asking, are some of the cars just too old to be on the tracks? CNN's Jeanne Meserve reports.
The exact cause of the DC Metro crash is still unknown. Part of the cause could be faulty control circuits and authorities are asking, are some of the cars just too old to be on the tracks? CNN's Jeanne Meserve reports.