A Police Constable took a claw hammer and killed his wife, his three-year-old son, and his 18-month-old toddler who lay in his cot.
Karl Bluestone, 36, burly and 6ft tall, also seriously injured his eight-year-old son, Jack. Only his seven-year-old, Jessica, managed to escape the carnage. She ran to her neighbour shouting: "My daddy is trying to hurt me."
By the time the police arrived at about 10pm at the semi-detached house in Gravesend, north-west Kent, Bluestone had hanged himself from a door in the garage at the end of the garden.
As the children's toys could still be seen scattered on the grass in the back garden yesterday, neighbours and colleagues were trying to make sense of Tuesday night's horrific events. There was talk of previous arguments between the husband and wife, there were rumours of work-related stress and depression, but nobody could comprehend how a well-liked man who appeared to be devoted to his family could pick up a hammer and beat his wife and children to death.
Their three-bedroom house in Riverview Park, a neat 1960s housing estate, was cordoned off yesterday as forensic scientists examined the building for evidence. Among the items they removed were boxes of family photographs.
The family car, a blue Mitsubishi Shogun, with personal number plates JIII BLU after Jill Bluestone stood at the front of the house.
Near by was a basket of flowers with the message: "Heartfelt thoughts to all the family. God Bless. From the Friends of Raynehurst School." Six large teddy bears were also placed at the scene.
On another card someone had written: "WHY? Safe with Jesus now. Thinking of those left behind."
Of the surviving children, Jack, who suffered serious head injuries, was described yesterday as being in a stable condition at King's College Hospital in London. Jessica, who suffered slight injuries, was discharged from hospital and was staying with relatives last night.
Bluestone had unleashed his devastation after Chandler, 18 months, Henry, 3, Jessica, 7, and Jack, 8, had finished playing with their seesaw, tricycle and plastic car, had eaten their dinner, put on their pyjamas and gone to bed.
Neighbours claim to have heard the husband and wife shouting at each other.
PC Bluestone is thought to have bludgeoned his wife in the kitchen at the rear of the house and then tried to hit his daughter, who was alerted by her mother's screams;she fled to the house next door. He then went upstairs to the bedrooms and attacked the three boys. Chandler was found in his cot in his parents' bedroom. Henry was found in the hallway at the bottom of the stairs. Jack was discovered wandering outside with his sister.
Paramedics took Chandler, who was critically injured, to Darent Valley Hospital, in Dartford, but he died several hours later. A post-mortem examination yesterday afternoon gave the cause of death for the three family members as "head injuries caused by a claw hammer". A spokeswoman for Kent police said: "The seven-year-old girl had knocked on the neighbours' door in a very distressed state and they took her in and called the police. Our officers came round expecting to find a domestic. They were faced with a horrific scene."
Lee Watts, 43, who lives with his wife and three daughters opposite the Bluestone family, described seeing the police and ambulance crews arriving at the murder scene.
"It was pandemonium, with cars arriving and tape going up. After a while they brought out the children. The baby was carried out in the arms of a paramedic and put straight into the ambulance, and the older boy was brought on a stretcher.
"The older girl was also carried. She was quite alert and was asking one of the officers what all the police tape was for. Later on, a private ambulance came and took the bodies away. It was shocking to see when I saw the children being brought out I thought, 'Oh my God, not the children'."
He said he had previously heard one "heated row" between the husband and wife.
PC Bluestone, who joined Kent police in 1987, went to work as normal on Tuesday and was due at work at 8am yesterday. Described as a quiet, unassuming but respected policeman, he was part of a rural tactical unit used against specific crimes in north Kent, such as criminal damage or vandalism. PC Bluestone's parents, Christy and Greg, former local Labour councillors who live in a street near by, were told the news of the tragedy while visiting their younger daughter in France. In a statement the couple said: "We loved our son. He was a man devoted to his children, dedicated to his job and filled with love for his wife."
Peter Snelling, a friend and neighbour of the police officer, said he had known him all his life. He said: "I can't believe what he has done to his kids. It seems so out of character as he adored them and they loved him." Mr Snelling said the officer had always been a quiet, introverted man who bottled up his feelings.
He added: "I have known him since he was a young boy and he was a smashing fellow, but you never know what goes on in people's lives."
Faye Bullock, who lives across the road from the family, said: "He was always with his children and used to walk them to school every day."
PC Bluestone grew up in Gravesend, a down-at-heel former industrial town on the south bank of the river Thames, with his two younger sisters. He moved into to the family house about eight years ago. It had been for sale for the past two months priced at £135,000.
He married Jill in Middlesbrough in 1994. It was his second marriage, and he had a 12-year-old daughter who lives with his first wife in Gravesend.
Mrs Bluestone worked in the accounts department at Essex County Council. The couple employed a childminder, who was at the house on Tuesday and is due to be interviewed by the police.
The parents of Mrs Bluestone, Alan and Judith Skerry, left their home in the North Yorkshire village of Great Ayton to travel to Kent yesterday.
Barbara Oates, the headteacher at Riverview Primary School in Dartford, which is attended by the two surviving children, said: "When the time comes for Jessica to return to us and for Jack to transfer to junior school, the staff and the children's friends will be ready to help them in any way possible as they start to rebuild their lives."