A judge praised the bravery of firefighters who risked their own lives in rescuing the family members from the blaze which engulfed their home in Leeds.
-> Police operation into firearms offences at Leeds garageAnthony Walters was given an extended prison sentence of 20 years today after being found guilty of arson with intent to endanger life.
Walters, 34, travelled from his home in Doncaster before setting fire to the house on Hill Top Mount, Chapeltown, in the early hours of January 24 this year.
Jurors heard Walters carried out the attack as he blamed the mum for the breakdown of the relationship with his own partner.
Geraldine Kelly, prosecuting, said: "He blamed her for his relationship breakdown and his inability to reunite his family."
Leeds Crown Court was shown CCTV footage of Walters approaching the property with a bottle of liquid in his hand.
Within two minutes of him walking away flames could be seen coming from the property.
The mum was woken up by the sound of the fire alarm.
-> Leeds city centre road reopens following police incidentShe could see an orange glow and smelt burning plastic.
The court heard she dialled 999 and was advised to take her children, aged 13 and five, into the attic and barricade themselves in.
Ms Kelly said: "They were advised to open a window, but she could not open it or smash it.
"They could not see with the smoke and struggled to breath.
"They waited for the fire brigade, lying on the floor."
Thick smoke and flames were coming from the property when firefighters arrived.
The prosecutor said: "The whole hallway was completely alight, with zero visibility due to the think black smoke.
"Normally they would wait until the heat had died down to progress through the property, but knowing there were occupants, they proceeded to the first floor."
Firefighters had to "sweep and feel" their way around the property but managed to rescue the victims.
Ms Kelly said: "The fire brigade is of the view that had they arrived a couple of minutes later all three would have been completely overcome by smoke, resulting in loss of consciousness and death."
Walters created a false alibi for himself when arrested. He claimed he had been at a friend's house on the night of the fire.
CCTV footage was recovered showing him travelling by train from Doncaster to Leeds then arriving in a taxi near to the property.
The taxi driver later identified Walters.
-> Man sent intimidating text message to teen victim in Leeds sex abuse caseWalters found not guilty of attempted murder but guilty of arson with intent to endanger life.
The court heard the mum and her two children were treated for the effects of breathing in smoke.
Ms Kelly said they continue to suffer psychological trauma as a result of the ordeal.
Walters, of Beckett Road, Doncaster, was told he must serve a custodial term of 15 years, followed by an extended licence period of five years.
Jailing him, judge Tom Bayliss, QC, said: "This was a cold, calculated, well-planned attack.
"You had ample opportunity to step back from what you set out to do.
"It was an act of revenge committed at a time of night when you must have thought that the victims were at their most vulnerable."
Praising the actions of the firefighters, the judge said: "Only the bravery of the fire service saved the lives of those three people.
"We owe a debt of gratitude to people who risk their lives to save lives."Detective Inspector Dave McDougal, of Leeds District CID, said: “Walters’ actions in deliberately starting the fire in the early hours of the morning could very easily have caused the deaths of a mother and her two young children.
“Had it not been for the courageous actions of the firefighters who rescued them from the burning property, the incident could have ended in tragedy.
“He has proven himself to be a very dangerous individual and we hope the significant sentence he has received will provide some degree of comfort and reassurance to the victim and her family."
A West Yorkshire Fire and Rescue Service spokesperson said: “You only need to look at the pictures of the damage caused by this fire to see that the family have had an incredibly lucky escape.
“We must take this opportunity to commend the swift actions of firefighters in responding to this fire and the skill and professionalism of our Control staff who received the 999 call – this vital teamwork between our staff was critical in the positive outcome to this incident.
“Had it not also been for the working smoke alarms in the property this fire could easily have claimed lives.”