Apparently Amtrak was having a bad day in Philadelphia the other day. One of their "Keystone" services from Harrisburg, Pennsylvania to New York City Penn Station ended up at Bala Cynwyd station instead. Bala Cynwyd is a small suburban town, west of Philadelphia, and not on Amtrak's North East Corridor which the Keystone services run on.
It seems there was a technical issue (I guess these days we have "issues", not problems or screw ups) with the train's cab control car.
Cab control cars are frequently used an so called "push-pull" train rakes. The locomotive is on one end of the train, the cab control car is on the other end, having all the necessary controls to operate the locomotive remotely. With this arrangement the locomotive does not have to be "run around" the train at the end of the line.
In any case, the on board crew on the above mentioned train tried to get the locomotive on the east end of the train (meaning towards New York City Penn Station), replacing the defective cab control car to continue on their journey. Normally this would be done by running the locomotive around the train at a suitable passing siding. However somehow they missed the run around area and ended up at the Bala Cynwyd station.
Here are some photos and a description of the event by John P. Almeida