Metro-North, the nation's largest commuter railroad, is still running at half capacity Tuesday. And Con Ed says its own work may have led to the power disruption that is vastly reducing service for tens of thousands of beleaguered commuters. "A preliminary review indicates that the feeder fault is likely related to work that was performed to disconnect the feeder for Metro-North's upgrade work," the company said in a statement.

Power to the railroad was disrupted last week after a feeder cable failed.  The back-up source had previously been taken off line for upgrades. Neither Con Ed nor MTA officials have explained why the railroad's New Haven Line, which serves 130,000 trips a day, was relying on just one power source. But in statement Monday, Con Ed said: "High-voltage transmission feeders are housed in oil-filled pipes. Removing these feeders from service is a complex process, which involves freezing the insulating oil in the pipe within a "freeze pit." These freezing operations are conducted routinely while working with high voltage transmission lines, and we perform numerous operations each year without incident."

"In this case, we have confirmed that the fault is located just outside of the "freeze pit" work area. In addition, the ground surrounding the work area was found to be frozen, and this unusual condition likely contributed to the feeder failure. We cannot recall a condition of this nature developing during any of our previous freeze operations."

But this time "a condition of this nature" did develop.

"We will be conducting a thorough review of the cause of the feeder failure once restoration activities are completed. The review will include a thorough examination of the failed cable once it is removed from the pipe as part of the restoration process, and will focus on understanding how this incident occurred to avoid future such incidents," Con Ed continued. "Metro North officials say it could be weeks before service is normal.  Trains are currently running at about 50% of normal service.  

On Sunday, Senators Richard Blumenthal (D-CT) and Charles Schumer (D-NY) called for an investigation into the incident.

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