Second child allegedly stabbed by mother in Blue Mountains attack dies in hospital

September 24, 2026 — 7:44pmAn infant has died in hospital five days after their Sydney mother allegedly stabbed the one-year-old and their two siblings inside a car in the Blue Mountains.The one-year-old died on Thursday after being rushed to hospital following the alleged attack on Sunday afternoon. The child’s five-year-old sibling was declared dead at the scene on Sunday, while their three-year-old sibling continues to fight for life in hospital.Forensic police place an evidence marker near a child seat at the crime scene in the Blue Mountains on Sunday. Two children were killed in the attack.Sitthixay DitthavongThe mother, a 42-year-old woman, was charged on Tuesday with the murder of her five-year-old son, and two counts of intending to murder and causing grievous bodily harm to the boy’s siblings, aged one and three. She appeared in court on Tuesday from her bed at Westmead Hospital, where she has been treated for self-inflicted wounds after allegedly stabbing her children.The woman will now face an additional charge of murder following the death of her youngest child. She will next appear at Penrith Local Court on November 20.The horrific scene was discovered by passing cyclists on Sunday, who administered life-saving first aid to the two surviving children before they were rushed to Westmead Hospital in a critical condition.The father, who was at work at the time of alleged attack, rushed to the hospital, where he was supporting his children as they underwent treatment. The one-year-old was in a critical but stable condition on Tuesday, before their condition declined in the past two days.Police attend the crime scene on Waratah Road in the Blue Mountains suburb of Valley Heights on Sunday.Sitthixay DitthavongDetectives are investigating whether an argument between the children’s parents was the catalyst for the attack, police sources told the Herald.The attack marked the fourth alleged domestic violence-related killing across NSW on the weekend, sparking renewed pleas from police for greater resources targeting the prevention of domestic and family violence.More to comeSupport is available from the National Sexual Assault, Domestic and Family Violence Counselling Service at 1800RESPECT (1800 737 732), the Men’s Referral Service on 1300 766 491, Lifeline on 13 11 14 or Beyond Blue on 1300 22 4636.Start the day with a summary of the day’s most important and interesting stories, analysis and insights. Sign up for our Morning Edition newsletter.Daniel Lo Surdo is a breaking news reporter for The Sydney Morning Herald. He previously helmed the national news live blog for The Sydney Morning Herald and The Age.Connect via email.From our partners