A BMW driver drove into the back of a stationary Peugeot at 70 mph killing a pregnant Penygroes woman and her unborn child, a jury heard today.

Craig Scott, aged 51, hit the Peugeot with such force he pushed it into an Audi killing Rebecca Evans and causing serious injury to her two year old son Cian.

He suffered serious brain injuries and fractures and was airlifted to hospital.

Rebecca Evans, an Encore stage school teacher, was declared dead at the scene, as was her unborn daughter.

Scott, from Armoury Drive, Heath, Cardiff, admits causing her death by careless driving but denies his driving was dangerous.

He also denies causing Cian serious injury by dangerous driving.

Catherine Richards, prosecuting, told Swansea crown court dangerous driving fell well below that expected of a competent and careful driver.

That, she said, was what the prosecution maintained Scott was doing when he failed to notice that traffic on the M4 at Port Talbot had come to a standstill.

The Peugeot 407 was being driven by Rebecca's partner Alex Evans.

He had come to a halt and put on the car's hazard lights to alert traffic approaching from behind.

But Scott had become distracted, said Miss Richards, and he failed to apply the brakes.

The accident happened shortly after 8am on November 29, 2016.

Mr Evans had been driving west towards the Penllergaer services where they were due to hand Cian over to Rebecca's mother while they went to work.

Just after Junction 38 the three lane motorway reduced to two lanes and it was not unusual for rush hour traffic to become congested.

Mr Evans noticed the BMW approaching in his rear view mirror.

"He (Scott) was not paying attention. He did not respond to what was taking place ahead of him.

"Road conditions were good and visibility was good. But he failed to see a stationary vehicle and was driving too fast for the traffic ahead of him.

"His driving was not just careless but dangerous.

"An accident investigator will say he was doing about seventy miles an hour at the moment of the collision," she added.

Scott later told police that he braked but was too late.

But, said Miss Richards, there wasn't any evidence that he braked at all.

Scott later told police that he had made a hands free telephone call to his workplace about five minutes before the accident.

But, said Miss Richards, that call had actually been made just seconds before the collision.

Scott also said he may have been distracted by something he saw on a bridge. But, said Miss Richards, the bridge had been some distance away from the scene of the collision and, in any event, he should have been paying attention to the traffic ahead of him.

The collision was filmed by a dashcam on board a lorry and the footage was shown to the jury.

The trial is expected to end later this week.