A father deeply affected by the loss of a baby killed his wife and two young sons four years later, an inquest has heard, before setting their bedroom on fire and embracing them as he too died. The destruction of a once-happy family followed a mental breakdown by Richard Smith, who was 37 and unfailingly took time off with his wife, Clair, on the anniversary of their second baby's miscarriage.

Smith, a quantity estimator, outwardly appeared to friends and neighbours to be the settled and thoughtful father of former times, a stalwart of the Pudsey Juniors football club in which his older son Ben, who was nine, was an eager player. The family had been to a cricket club social two days before the tragedy in December last year and Smith chatted to neighbours while giving their car its usual weekly wash.

Leeds coroner's court was told that soot was noticed covering the windows at the three-bedroom, detached house where Smith and his wife, who was 36 and worked in accounts at a local store, lived in the small town of Pudsey between Leeds and Bradford.

Det Supt Paul Taylor of West Yorkshire police, told the inquest that emergency crews found the family cradled together on the bed in the smoke-filled room. "Clair was in the position you would imagine was natural to sleep in, Ben was laid across his mum, Aaron between them and Richard embracing all three," he said.

Smith had stabbed and strangled his wife and stabbed Ben and his one-year-old brother, Aaron, before blocking the doors and windows and setting fire to the mattress. They are thought to have died a day earlier, because the latest door in Ben's advent calendar had not been opened.

"Four years ago, almost to that day, they lost a baby, Jake," said Taylor. "The box containing baby Jake's ashes was found in the crook of Clair's arm."

Pathologist Dr Brian Rodgers who carried out the four postmortems said that Clair and Aaron had died before the fire was started but Ben's wounds in the chest, neck and arm had not been fatal. He and his father had died from inhaling smoke and fire gases with the boy possibly suffocated by having his head pressed tightly to his father's chest. Smith also stabbed himself in the neck but not fatally.

The West Yorkshire coroner, David Hinchliff, said that the death of their baby had deeply affected the couple and might have been the cause of depression suffered by Smith turning into an overwhelming breakdown. Recording three verdicts of unlawful killing and one of suicide, he said: "It would appear that Richard has undergone some aberration, some problem, affecting his mental health which caused him to take the action he has. It was a concerted act of destruction of his family and his own self-destruction.

"It is my view that, having been the perpetrator of all that had happened and being faced with the enormity of whatever was preying on his mind at the time and causing an aberration of this immensity, he has taken his own life."