Police are investigating a deadly stabbing after a man was found injured on a southbound 4 train at the 14th Street Union Square station in Manhattan.

Another passenger on the train alerted the conductor that the victim was partially unconscious, police say.

That victim, an unidentified 32-year-old man from the Bronx, had stab sounds in his chest and back, according to police. He was taken to Bellevue Hospital where he was pronounced dead.

Service on the 4, 5 and 6 subway lines was impacted for several hours throughout the morning on Saturday while police gathered evidence from the train where the man was found.

As of Saturday afternoon, the NYPD had not reported any arrests in the case.