Projectile was a different train, but around the same time.
http://philadelphia.cbslocal.com/2015/05/13/septa-says-commuter-train-hit-by-projectile-just-before-amtrak-train-derailed/
...A Philadelphia commuter train was hit by a projectile about 20 minutes before an Amtrak train derailed a few miles up the track...
A commuter train. Thanks.