text: Alesha O'Connor, Rhodri Miller, Corey Price, all 17 and from Barry, Vale of Glamorgan, and Margaret Challis, 66, from Merthyr Tydfil, were killed near Storey Arms, Brecon, in March 2015.
  The Aberdare inquest heard Rhodri was driving the teenagers in one car.
  The coroner concluded all four died as a result of a road traffic accident.
  The inquest was told Rhodri's car was one of seven vehicles in a convoy going on a drive from Barry on the night of 6 March.
  Rhys Hunter, a passenger in the car, said Rhodri had passed his test a few days earlier.
  He said before the group set off someone warned him "be careful, we're on a mountain" and at one point during the journey the driver ran a red light.
  Minutes before the crash, Mr Hunter took a picture and the speedometer in the car he was in showed 75 mph (120km/h).
  But Mr Hunter said Rhodri was not trying to catch up with the vehicle in front of him and had not been trying to overtake another vehicle.
  "Rhodri started to lose control and we collided with the other car," he said.
  "I'm not sure why it happened or why the car was out of control. Probably because of the way it was driven."
  Joseph Fetter, who was driving behind Rhodri's car, said he was driving consistently around five car lengths behind and no racing had taken place, but he had seen Rhodri's brake lights come on several times.
  "I think it was inexperience that made him lose control," he said. "I wasn't pushing him on - I didn't know the road at all. It was dark."
  Passengers in some of the other vehicles said Rhodri was not overtaking but did lose control of his car on the bend, swerving from one side of the road to the other.
  But survivor Emlyn Williams, who was in the other car involved in the crash along with friend Mrs Challis, disputed some of the evidence.
  "The car was coming down by a bend. I saw another car overtaking it. The car hit me, that was it," he said.
  "The only thing I knew was a bang, the windscreen broke and the airbag came out.
  "I tried to get out and see to Mrs Challis. I went to the other car. It was quiet, silent. There was no opportunity to steer out of the way."
  Drivers and passengers in vehicles travelling in the direction of Merthyr Tydfil described in police statements seeing the cars leave a lay-by at Storey Arms minutes before the collision.
  The inquest was told they pulled out too quickly and too close to each other. One witness said: "Boy racers. It's obvious they were on a mission."
  Dyfed-Powys Police Insp Gary Jones told the inquest messages found on mobile phones showed those in the convoy had discussed speed.
  One read: "It's madness. Everyone's racing there are 9 cars" while another read "why would I want to go along cars with turbos - I'll be the slowest there".
  PC David Stacey, who investigated what had happened, said it was "like nothing I had seen in 20 years service. It was a distressing scene".
  He told the inquest he believed what Mr Williams had seen was Rhodri's car out of control, possibly caused by approaching the unmarked bend at too high a speed and braking in the turn, but not overtaking.
  Rhodri and Corey were pronounced dead at the scene while Alesha and Mrs Challis died at Prince Charles Hospital, Merthyr.
  The inquest heard new road signs had since been put in place on that section of road but the coroner recommended that signage should warn about the upcoming bend.
  In a statement, Rhodri's family described their son as "the child every parent would dream of", adding: "Our hearts have been ripped out, and nothing is the same."
  The family said they would like to see lessons learned and for young drivers to be made to realise the implications of serious car accidents in the same way as those who are caught speeding do.
  The family also called for more rigorous conditions to be placed on new drivers.
target: A fatal combination of inexperience, speed and peer pressure led to the deaths of four people in a two-car crash, an inquest has heard.