(NEW YORK) — A mother was killed and her two young children were critically injured after their roommate attacked them with a hammer in their New York City apartment, police said.

Police responded shortly before 3 p.m. ET to the report of an assault in progress at an apartment in Brooklyn, according to New York City Police Department Chief of Patrol John Chell.

Officers found the three victims in the second-floor apartment in Sunset Park and they were transported to a local hospital, where the 43-year-old mother was pronounced dead, Chell said.

Her children — a 5-year-old boy and a 3-year-old girl — are “fighting for their lives” after the “brutal” attack, he said.

A suspect — who also lived in the apartment — was apprehended as he was trying to leave the apartment building and was placed under arrest, according to Chell.

The suspect and victims were not publicly identified. Police said the suspect has no relation to the victims.

A hammer was recovered at the scene, police said.

It is unclear what prompted the attack, said Chell, who called the incident “horrific” and a “senseless act of violence.”

The attack occurred in a three-bedroom apartment. The mother and her two children lived in one room, while the suspect and his 9-year-old son lived in another, Chell said. The third room is occupied by one person.

“We all have to pray for these young kids, these two young kids fighting for their lives,” New York State Assemblyman Lester Chang told ABC New York station WABC. “And I can only imagine what the father has to go through.”

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