A homeless woman was fatally struck by a Manhattan subway train early Saturday, police said.

The woman, believed to be in her forties, was on the tracks when she was hit by the subway on the 1/2/3 line at 34th Street and 8th Avenue in Penn Station at around 6:25 a.m., cops said.

The train’s operator tried to brake in time, but ended up striking the woman, police said.

First responders with the FDNY tried to save the woman, but she was pronounced dead a short time later.

It wasn’t immediately clear how the victim ended up on the tracks, police said.