Late last night, police responded to an awful scene in Brooklyn: Five people—four young children and their mother—were found unconscious with stab wounds in a Sunset Park apartment. All the victims would die from their wounds, and a man, apparently a cousin, was taken into custody.

Police say that at 10:44 p.m. they responded to a call about a stabbing at 870 Fifth Avenue. Inside, they found the five family members unconscious. William Zhuo, one-year-old, Amy Zhuo, seven-year-old, and Linda Zhuo, nine-years-old, were all pronounced dead at the scene. Emergency responders took their mother, Qiao Zhen Li, 37, to Lutheran Hospital and brother Kevin Zhuo, 5, to Maimonides Hospital; both died at the hospitals.

Witnesses say that the family's cousin was taken into custody. The cousin was described as being bloody and shoeless—the Post has a photograph and spoke to a neighbor, "He [the suspect] was bizarrely calm. He was completely composed and answering their questions — even as they brought out two black bags with the kids in them." The Post adds, "Cops seized a machete and scissors from the home as evidence, a law enforcement source said."

It's believed the mother's sister called 911. A neighbor said, "She’s crying, and her friend told me her family was cut, and the kid was cut and there were so many bodies inside in the room."

A law-enforcement source told the Post," The father walked in and grabbed [the stabber] and tried to stop him but it was too late" while a neighbor told the Daily News, "The father was freaking out. He just came home from work and saw the police and they told him. He was hysterical."

Another neighbor said, "I always see (the kids) running around here. They run around by my garage playing. They run up and down screaming. They’re little kids ... that’s so heartbreaking. Innocent kids, my God."

[UPDATE] Police have arrested the cousin of the children's father, 25-year-old Mingdong Chen. Police told the Times that Chen became violent during his interrogation at the 66th Precinct, and hit a police officer.

NYPD Chief of Department Philip Banks said police hadn't been called to the address before. “What we have is just a normal family who unfortunately was the victim of an unspeakable act."

Chen is charged with one count of first degree murder, four counts of second degree murder, and five counts of criminal possession of a weapon.