More than 100 firefighters reported to a suspicious three-alarm fire that broke out at Penn Station's subway station at West 33rd Street and Eighth Avenue in midtown Manhattan, the New York City Fire Department reported via its Twitter feed.
The fire broke out below the subway grade just before 2:30 a.m. and brought more than 100 firefighters to fight the flames, NBC New York reported.
The cause of the blaze was not immediately clear, Fox 5 News New York reported.
At around 5:30 a.m., FDNY tweeted that the fire was under control. No injuries were reported.
A and E trains temporarily bypassed 34th Street, but authorities say A, E and C trains are back to normal - they are just slowing down on approach to Penn Station. Long Island Rail Road service is also impacted. Commuters should anticipate delays and cancellations.
The fire is thought to have started at a construction site by the station, according to NBC New York.
On Monday, one person was reported dead after smoke filled a subway car in downtown Washington, D.C. At least two people were also critically injured.
A total of 84 patients were transported to area hospitals, and scores more were evaluated at the scene, said Khalid Naji-Allah, a program analyst with the District of Columbia Fire Department.
Morgan Dye, a spokeswoman for the Washington Metropolitan Area Transit Authority, said the National Transportation Safety Board is looking into the cause of the smoke. A representative from the NTSB declined immediate comment.