3 found dead in L.I. townhouse

A man and two women were found dead inside a Long Island house on Friday afternoon — and an infant was found inside unhurt, police said.

Shortly after noon, a worried relative called 911 to summon Suffolk County police to the home in Fairfield Hills South, a gated rental townhouse complex in Farmingville, about 55 miles east of Manhattan, police said.

The relative told cops that he went to the house to check on someone, and he believed the people inside were dead.

Inside, police found three people dead of gunshot wounds. They were identified as Richard Castano, 31, and Diamond Schick, 24, who both lived in the house, and Nyasia Knox, 20, of Georgia.

Police said a door at the home had been kicked in and the door jamb was broken — and officers weren’t sure whether the slaying took place Thursday night or Friday morning, Newsday reported.

The baby in the house, who is less than 1 year old, was in a room with its door closed, said police. The child was taken to a hospital for observation, Newsday said.