Four people were shot to death in a suspected murder-suicide Wednesday at a New York City Housing Authority building in the Bronx, police sources say. 

The NYPD was called shortly before 9:30 a.m. to the Castle Hill Houses on Lacombe Avenue in the Castle Hill section of the borough. 

Police sources said the victims were found inside a fifth-floor apartment with gunshot wounds. They were pronounced dead at the scene.

They were identified as a 75-year-old women, who lived in the building for many years, a 26-year-old woman, described as being a member of the family, and two men, one a 44-year-old relative.

Police sources say the gunman was one of the men, and that he called from the apartment to a relative who lives elsewhere with a message to check up on the family. He then apparently took his own life.

The person who carried out the welfare check contacted police, who arrived and found the victims and a firearm.

"Those people that passed away are some people who were loved and someone we care about," resident George Medina said.

The older woman who was killed was remembered as always helpful around the Castle Hill Houses.

"I've known her for 49 years. She was the nicest lady," neighbor Margarita Rivera said. "It's very sad. I'm very upset."

Neighbor Jeannette Martinez described the older victim as "a wonderful, wonderful person."

The medical examiner's office will now work to determine the exact causes of death. No further details have been provided.