A father accused of killing three generations of a family in a house fire was jealous of the attention his girlfriend gave to their blind and deaf daughter.
Carl Mills, 29, killed his own baby daughter, her mother and grandmother after torching their home on the day the child was released from hospital, a murder trial heard.
Kayleigh Buckley, 17, six-month-old daughter Kimberley and grandmother Kim, 46, were all trapped in their home when it was engulfed in flames.
Newport Crown Court heard how Mills started the fire after he became convinced Kayleigh had another man in her bedroom.
But the only people inside were the family - who were celebrating Kimberley's homecoming after being born prematurely at just 1lb 9ozs in hospital.
Neighbours saw Kayleigh banging on the windows and screaming for help but they were unable to save her.
Prosecutor Greg Bull said: "The three victims didn't have a chance."
He said they were unable to get down the stairs because of where the fire was set.
He said: "Within minutes it became impossible to save the people inside. Neighbours did all the right things but they were confronted with a scene which can only be described as heartbreaking.
"Kayleigh was in the window of a smoke-filled room crying for help for her and her baby.
"People were calling out 'Jump' but she wouldn't leave her baby. Neighbours could hear her saying she was on fire.
"Then within a few minutes there was silence. All of the victims died in the fire."
The fire had been started just hours after baby Kimberley had been discharged from hospital after being born prematurely. She was one of twins but her sister Angel had been stillborn. Kimberley was deaf and blind and had underdeveloped lungs as well as problems feeding.
Prosecutor Gregory Bull QC told the jury how Mr Mills, who was living in a tent in the garden of his girlfriend's home, had become increasingly resentful of the attention she had been giving to their daughter.
The court heard how during Kimberley's time in hospital a care plan had been drawn up for her which involved her mother Kayleigh and grandmother Kim.
Although Mills was allowed to see Kimberley, he was not allowed to care for her due to his alcohol issues and his refusal to accept professional help, the jury heard.
In response to the care plan, Mills sent a text message saying he hoped the baby died. He had also sent texts threatening to kill the family.
The jury heard that despite this Kayleigh, who met Mr Mills via the internet when she was 15, was still infatuated with him.
The jury was told that Mills had 'magnetic control' over Kayleigh. Mr Bull described Mills as a controlling and jealous man.
"His abusive, controlling and irrational behaviour was demonstrated in a number of ways. He tried to drive a wedge between Kayleigh and her school friends," he told the jury.
On the afternoon of 17 September, Kimberley was discharged from hospital. But by 03:30 the next day she had perished, along with her mother and grandmother, in a fire at their home.
The trial continues.