Luke Pirie struck Harlow Edwards with his Ford Focus at 50mph having just sent a series of texts to his partner, a court heard yesterday.
Pirie, 23, was in a “hurry” when his car collided with her and two other children on an unclassified road close to the A94 in Perthshire.
Jason Wakeford, director of campaigns for Brake, the road safety charity, said: “This is a tragic, traumatic and chilling reminder of what can happen when distracted by using a mobile phone behind the wheel.
“Driving is one of the single most dangerous tasks we do on a daily basis and it needs full attention to do so safely.
“Motorists should switch off their mobiles and put them away in the glove box, out of reach, when on the road.”
The High Court in Edinburgh heard that Pirie had left work at Scone Airport at 12:30pm on 13 October 2016 “in a bad mood”. He had spent the morning calling and texting his partner Heather Eaton, whom he suspected of being unfaithful to him.
He left work, intending to confront Ms Eaton at her home.
Prosecution lawyer Iain McSporran QC told the court Pirie was seen overtaking cars in Balbeggie, Perthshire, at a speed which broke the 30mph limit. He used his iPhone to make a Facetime call to Ms Eaton before coming to a junction with an unclassified road known locally as the Coupar Angus Road.
The court heard that, as he came up to the junction, three other cars, including a Citroen indicating right, had stopped on the road. Pirie attempted to overtake the waiting cars and struck the Citroen as it moved out.
Pirie then lost control of his car, which struck a wall as the children were walking by.
Doctors said Harlow sustained serious injuries and her death was “inevitable and rapid”.
Yesterday, Mr McSporran told the court how Harlow’s mother is unable to cope with the loss of her daughter. “She has difficulty sleeping. She constantly thinks about not being with Harlow when she lost her life.
“She feels robbed of a lifetime of memories and she cannot put into words the grief that she is currently suffering.”
Mr McSporran was speaking after Pirie, of Forfar, pleaded guilty to causing death and injury by dangerous driving.
The advocate depute told the court that Pirie appeared “worked up” as he spoke on his mobile phone, adding: “At 14:46, he texted ‘I’m coming home’ followed by ‘cheat’ and ‘You’ve obviously done something stupid that you’re afraid to talk to me.’
“He continued to send and read images and text messages after driving away from his work – he had not been scheduled to leave work so early.
“It is clear from the number of calls and messages and the content of those images which can be read that he was upset and angry with his partner.
“The tone of his text messages then changed to pleading with her to phone him. She sent two messages at 15:12 in strong terms telling him to ‘get a grip’ of himself.
“These messages were read by him at 15:17. Within four seconds of reading them, he sent her a message stating ‘I’ve crashed one Heather’, followed five seconds later with ‘Heather I’ve been in a crash’.”
The children who survived the collision sustained brain injuries and fractured bones. Surgeons had to place a metal plate into one child’s head.
The other child is reported as suffering from nightmares and anxiety.
Mr McSporran also told the court that the accused had initially claimed the children had “stepped out in front of me”.
Defence advocate Mark Stewart QC said he would reserve his mitigation until sentencing, which will take place at the High Court in Glasgow on 4 October.