The cause of the crash wasn't immediately known. The National Transportation Safety Board said it was sending investigators.

Hoboken, which is NJ Transit's fifth-busiest station with 15,000 boardings per weekday, is situated just across the Hudson River from New York City. It is the final stop for several train lines and a transfer point for many commuters on their way to New York City. Many passengers get off at Hoboken and take ferries or a PATH commuter train to New York.

"We have multiple injuries, multiple critical injuries right now," Jennifer Nelson, a spokeswoman for NJ Transit, said. Rail service was suspended in and out of Hoboken,

She said she doesn't know yet how fast the train was going when it crashed through the bumper. TV footage and photos from the scene showed the rail car was mangled.

Rich Scardaville, who was aboard the train, told the Wall Street Journal that it approached the station normally but suddenly "lurched forward at the last minute."

Then, he said, there was an "ungodly loud bang, like an explosion" before the lights went off and "everyone went flying."

Passenger Bhagyesh Shah said the train was crowded, particularly the first two cars, because they make for an easy exit into the Hoboken station. Passengers in the second car broke the emergency windows to get out.

"I saw a woman pinned under concrete," Shah told WNBC-TV in New York. "A lot of people were bleeding; one guy was crying."

Brian Klein, whose train arrived at the station after the crash, told the Wall Street Journal that transit police ushered everyone aboard his train into a waiting room, "then quickly started yelling, 'Just get out! We don't know if the building is going to hold.'"

The train had left Spring Valley, New York, at 7:23 a.m. and crashed at 8:45 a.m., said NJ Transit spokeswoman Nancy Snyder.

"It simply did not stop," WFAN anchor John Minko, who witnessed the crash, told 1010 WINS. "It went right through the barriers and into the reception area."

NJ Transit provides more than 200 million passenger trips annually on bus, rail and light rail lines. More than 100,000 people use NJ Transit trains to commute from New Jersey into New York City daily.

A crash at the same station on a different train line injured more than 30 people in 2011. The PATH commuter train crashed into bumpers at the end of the tracks on a Sunday morning.