PHILADELPHIA (WPVI) --Officials may have finally tracked down the source of the problem that put more than 100 SEPTA regional rail cars out of service.
The maker of the new Silverliner V trains says it's due to faulty welds.
That weld is part of the suspension system, and involved a load-bearing beam.
Now that the problem's been identified, the train manufacturer, Hyundai Rotem, says two possible replacements beams are being considered.
The company blames the bad welding job on one of its subcontractors.
But that office did not return emails or calls for comment to the Associated Press.
SEPTA has not given its official determination of what caused the cracks.