One child was killed and three others, including two siblings and an adult woman, were hospitalized in critical condition following a stabbing incident in the Blue Mountains township of Valley Heights on Sunday.

Police and emergency responders were alerted at approximately 12:45 p.m. after passing cyclists discovered the woman and children inside a car. The cyclists administered first aid at the scene, but one of the children, believed to be between six months and four years old, died instantly. The other two children, who are siblings, and the woman, estimated to be in her 40s, were transported to Westmead Hospital where all three underwent emergency surgery.

Authorities suspect the woman inflicted injuries on herself, though she remains in critical condition. Police Superintendent John Nelson confirmed that while the woman is known to the children, the precise nature of her relationship to them has not been officially confirmed. Police have spoken with the children’s father, who was reportedly at work when he received the tragic news. Attempts to contact other family members were ongoing.

Supt. Nelson described the scene as profoundly distressing, particularly for the members of the public who encountered the victims. He noted the trauma faced by those passing through the area, which is typically frequented by local residents as well as commuters from the nearby Great Western Highway.

Residents of the street where the car was found reported no prior disturbance and indicated they did not know the woman or the children involved. One local described the neighborhood as close-knit yet acknowledged that the particular road sees regular traffic from commuters.

Supt. Nelson also stated the injured woman was not previously known to police and confirmed that no other suspects were being sought in connection with the incident. Authorities classified the event as another tragic occurrence during a weekend marked by multiple fatal incidents across New South Wales.