New rail lines are stacked up in an area near the site where a deadly train derailment occurred earlier in the week, Friday, May 15, 2015, in Philadelphia. Amtrak is working to restore Northeast Corridor rail service between New York City and Philadelphia. Service was suspended after a train derailed in Philadelphia on Tuesday night, killing eight passengers and injuring more than 200.

New mystery in train crash: Was it hit by a flying object?

The windshield of the Amtrak train was shattered in the accident but one area of glass had a breakage pattern that could be consistent with …