A man drowned after he attempted to save a 4-year-old boy who fell into the Hudson River off a Yonkers marina, authorities said.

The unidentified 40-year-old man jumped into the waters, along with numerous other good Samaritans, after the boy fell in at around 6:50 p.m., Yonkers police said.

NYPD harbor units who assisted Yonkers police in the rescue recovered the boy who was taken to St. John’s Hospital for evaluation, officials said.

The man was pulled from the river an hour later and taken to St. Joseph’s Hospital where he was declared dead, officials said.

It remains unclear how the boy fell into the water and what the man’s relationship was to the child.