NBC New York: Details on Mystery 'Soiled Train' Better Left Unsaid: MTA

"A soiled train. The mind boggles," one straphanger tweeted. "Be afraid. Be very afraid," tweeted another

The curiosity of New York commuters was piqued Monday by an unusual subway service update -- but the MTA is assuring people they don't want to know the details.

The New York City Transit Subway Twitter account tweeted about 9:30 a.m. that northbound F and M trains were running express from W 4 St to 34 St "while we remove a soiled train from service at 14 St."

The announcement had many New Yorkers wondering what had happened to the train, and just how bad the problem was. "A soiled train. The mind boggles," Robin Wigglesworth tweeted. Read more here.