CBS New York reported that the transit train had struck a wall after entering the station in Hoboken.
Fox News is reporting that more than 100 people are believe to have been hurt.
It happened at around 8.30am at Lackawanna Station, close to the waterfront with the Hudson River, opposite Manhattan island and about a mile away from downtown Jersey City
Images of the scene posted on Twitter showed what appeared to be debris from the roof and supporting pillars strewn across the platform with a carriage twisted sideways on to a platform.
Another image showed wreckage, cables and pipes dangling from the building’s ceiling, which appeared to have collapsed.
One tweeter posted a picture of a man clutching his head with blood down his arm and T-shirt.
An anchorman for CBS affiliate WFAN told its sister station 1010 WINS: “It simply did not stop. It went right through the barriers and into the reception area.”