Four sleeping children were murdered after being trapped in their bedrooms when their house was torched with petrol bombs in the dead of night, a court has heard.
Zak Bolland, 23, launched the fatal attack after being involved in a feud with the victims' 16-year-old brother Kyle Pearson, a jury at Manchester Crown Court was told.
The family had warned about threats that they received, and police were at the house just hours before it was torched, despite officers fitting a letter box cover aimed to stop arson attacks, the Daily Telegraph reports.
Bolland along with David Worrall, 25, removed a fence panel from the garden of Pearson's home, smashed a kitchen window and tossed in two lit petrol bombs, it is alleged.
One landed near the stairs, blocking the only exit to the ground floor and trapping the victims upstairs as flames engulfed the three bedroom mid-terrace house on Jackson Street, Walkden, Greater Manchester.
Demi Pearson, 15, her brother, Brandon, aged 8 and sister, Lacie, aged 7, sleeping in a front bedroom, all died in the blaze, which was started at around 5am on December 11 last year.
Paul Reid QC, prosecuting, told the court: "Their apparently lifeless bodies were recovered by the firefighters who attended and battled their way through the heat, smoke and flames."
Their mother, Michelle Pearson, 35, was rescued along with her youngest daughter, Lia, aged 3, who died in hospital two days later.
Kyle Pearson managed to escape with a friend, Bobby Harris, who was also staying at the house.
The teenager saw the light from his sister Demi's mobile phone at the window before she coughed in the thick smoke then appeared to fall away from the window, the court heard.
The firebombing was the culmination of a series of retaliatory attacks between Bolland and Kyle Pearson, Reid told the jury of five women and seven men as the prosecution opened the case at the start of the trial.
Bolland and Kyle Pearson had been friends until the accused's Ford Focus was set on fire around November 25 last year, about two weeks before the fatal attack, and he blamed the teenager.
The defendant demanded £500, sending harassing text messages, including one demanding: "Fire letter box I want my £500."
Both sides launched attacks, breaking windows in each other's homes with Bolland threatening to fire bomb Kyle's house, the court heard.
The threat led Michelle Pearson to call police on November 26 and as a result the fire service fitted a letter box cover.
But due to an "apparent misunderstanding" police decided to take no action against Bolland for smashing windows at Michelle Pearson's home - and days later he was back, "laughing" that he had escaped police action and shouting "grass", the court heard.
Michelle Pearson again called police and asked for a restraining order but two days before her children were murdered, her bin was set on fire and the word "grass" was spray-painted on her house.
The day before the attack the three defendants spent the day drinking before Bolland and Worrall made their first visit to Jackson Street around half past midnight on December 11, four hours before the fire.
Bolland and Worrall attacked the door before Bolland shouted: "Watch, all your family's getting it, they're all gonna die."
When police arrived they took a statement from Michelle Pearson, one officer checking on the youngsters upstairs, who were asleep.
Kyle Pearson was "really worried" they would return so he got a door not attached to the frame and wedged it behind the front door.
The court heard that he later woke up in his smoke-logged bedroom to hear his mum shouting there was a fire.
He and Bobby Harris climbed out of their bedroom window onto a canopy above the front door to escape.
Michelle Pearson was found first on the bathroom floor and carried to the front garden.
In the larger front bedroom Brandon was found lying face down with his head towards the landing as if he had been trying to crawl out of the room.
Lacie was on the floor with her head towards her brother as if she had been following him.
Demi was found on the bottom bunk bed, her feet on the floor with her hands stretched out to the open window.
It looked like she may have directed her younger siblings to open the door and she had then tried to open the window, the court heard.
Lia was the last to be found, lying in the bath.
All the children were laid outside while paramedics worked on them, but only Lia showed signs of life.
But she suffered devastating injuries and life-support was withdrawn two days later. Michelle Pearson survived but is still seriously ill in hospital.
Bolland, his girlfriend Courtney Brierley, 20, and father-of-one Worrall all deny four counts of murder.
They also deny three counts of attempted murder relating to Michelle Pearson, Kyle Pearson and Bobby Harris.
Bolland has admitted reckless arson, a charge denied by the other two.
Bolland admits he had been drinking beer and taking cocaine and admits throwing the second petrol bomb but claims he intended only to damage the house, which he thought was not occupied, he claims.
Worrall claims he thought they were only going to set fire to wheelie bins and denies throwing a petrol bomb.
Brierley claims she did not know the two men had petrol bombs and claims Bolland had a "controlling influence" over her.
The trial continues.