A passenger who survived a Thatcham school minibus crash in which three staff members died has relived the moment the vehicle suddenly lost speed and was hit by a lorry.

Svilen Mihov was sitting alongside driver Catherine Gardiner when the minibus carrying students from a specialist autism school crashed on a section of the M4 with no hard shoulder due to roadworks near junction 14 for Newbury on October 11 last year.

READ MORE: M4 crash victims confirmed as three members of staff from Prior's Court School in Thatcham

Passengers Jay Aleixo, 44, from Thatcham, and Lorraine MacLellan, 60, from Farnborough, died at the scene.

Miss Gardiner, 52, of Reading, died at John Radcliffe Hospital the next day.

All three worked at Prior's Court in Thatcham.

Three students from the school were also injured in the crash.

Mr Mihov told an inquest at Reading Town Hall on Wednesday that the minibus suddenly shook and he heard a loud revving noise before the vehicle slowed down "rapidly".

Scared, he said he turned to Miss Gardiner, who he said held onto the "gear box" and shouted "oh my God" twice.

Moments later the lorry crashed into the back of the minibus.

The inquest was shown dash cam footage appearing to show a box van overtake the lorry and drive in front of it before quickly swerving out of the way.

The lorry, which was travelling at around 52mph and carrying around 12 tonnes of load, had little time to avoid the minibus.

Its driver, Graham Scivier, crashed into it despite braking and swerving in a desperate attempt to avert the crash.

Stephen Hall, who was driving the box van, when asked to describe what he saw of the minibus before moving out of the way, said: "It was as if someone had taken the foot off the accelerator and went backwards.

"It was just a wall coming towards me."

Mr Scivier told the hearing his vision was blocked by the box van and he had little time to act after the van "swerved out of the way".

He said there was nothing he could do.

Mr Hall said he tried to stop to call the emergency services after the accident, but could not do so until a "couple minutes later" because of roadworks on the hard shoulder.

"I wish I could have made it earlier," said Mr Hall. "It might have made a difference, but I couldn't."

The hearing was adjourned until Thursday when it is expected to conclude.