Washington accident highlights struggles of transit agencies

On June 22, nine people were killed and scores were hurt in a two-train collision on Washington's Metro system. It was the worst accident in 33 years on the transportation network which serves the District of Columbia and neighboring suburbs in Maryland and Virginia.

The tragedy raises questions again about the funding and safety of public transit systems and the cause remains under investigation. The Baltimore Sun reported that the train that caused the accident had some of the oldest rail cars in the Metro fleet. Computer failure is being investigated as a cause.