Danny Warby, 28, was driving the 13.6-tonne light goods vehicle along the A141 at Wyton on June 6, 2014, when he opened a text message on his phone, said Helen Guest, prosecuting. His vehicle crossed the white line in the centre of the road and clipped an oncoming lorry, showering two cars in debris, before crashing into a Renault Clio which was also in the oncoming line of traffic, Peterborough Crown Court has heard. The Clio was being driven by police officer Sharon Garrett, a mother-of-two, who was on her way home from work. She was pronounced dead at the scene. Warby denies a single count of causing death by dangerous driving. Ms Guest said: Mrs Garrett, in the short time available to her, had started to take evasive action towards the grass verge as the lorry headed towards her, but she was unable to prevent a collision. Both vehicles landed on their sides in a ditch at the side of the road. Ms Guest said Warby, of School Road, Runcton Holme, near Kings Lynn, had opened a text message on his phone one minute and six seconds before the time of the crash, with the precise time of the crash established by tracking data from the lorry. She said he had no hands-free kit or cradle for the phone in the lorry. Its possible he didnt read the text immediately, just opened it, she said. After all, after [he drove past] the safety camera there was a bend and you have to steer round bends and in the meantime after opening the text, where was the phone? What was he doing with his hands, what was he thinking? The collision took place on a fairly straight stretch of the road... after all the bends and junctions and the more dangerous manoeuvres, this accident happened on a relatively straight stretch of road, when, if a person might be that way inclined, it might present an opportunity to read a text. She added: If youre interacting with a mobile phone, your eyes arent on the road and your two hands arent on the steering wheel. The fatal crash happened close to RAF Wyton, near Huntingdon. Warby had completed several short journeys that day in the lorry which was carrying a crane and construction materials. Ms Guest said Warby had been diagnosed with obstructive sleep apnoea in late 2015 and his defence lawyers would argue that Warby experienced a micro-sleep just before the crash. The prosecution case is that Warbys reaction to apply the brakes after the first collision was rapid, and not consistent with a person who had been asleep, said Ms Guest. The trial continues.