A man was killed when he fell onto subway tracks at the Port Authority station and hit the third rail Thursday morning, cops said. 

The straphanger fell onto the southbound A line tracks at the 42nd Street-Port Authority station around 7:10 a.m., just ahead of the morning rush, police said. 

He made contact with the third rail, cops said. 

The man, whose identity was not immediately known, died of his injuries, police said. 

By the afternoon, police did not know how he fell, but said he was not the victim of a crime. 

The incident caused some morning delays on the A, C and E lines.