Drivers caught up in the horrific accident on the A14 described how the accident happened in less than a second.

William Elbrow, from Hawthorn Drive, Thrapston, was killed in the accident on May 4 last year.

Tearful Lucy Pembroke, who was travelling as a passenger in a navy blue Vauxhall Vectra, just behind the lorry, said: "I remember the brake light on the lorry and in under a second there was like an explosion.

"The lorry swerved to the left and to the right as if he was trying to control it. It went in front of us and went into the crash barrier."

Another motorist told a jury at Cambridge Crown Court he feared for his life as the lorry driven by Michael Coombes, from Stowmarket, crashed into the Elbrow family's Mitsubishi 4x4, which was towing a caravan, scattering debris across the carriageway.

Parents Simon and Louise Elbrow and children Olivia, three, Thomas, six, and William had been driving from their Northamptonshire home for a weekend at the seaside when tragedy struck at Stow-Cum-Quy, near Newmarket.

Paul Hodgkinson, who was driving a Mercedes Sprinter Highways Agency response vehicle, added: "I was traumatised and thought that would be the end of my life. I was very shocked."

Other witnesses at court yesterday described how they saw events.

Mr Hodgkinson said he had been driving home after finishing his shift when he was slowed by a traffic jam.

He could see blue lights in the distance and was slowing down, mindful that he wanted to help police officers with an incident on the road.

He then said he looked in his mirror before seeing a HGV and hearing something resembling an explosion.

Mr Hodgkinson said to his passenger that they might get caught up in the incident before his vehicle was "shunted forward", colliding with a BMW motor car.

He added: "Then I went uncontrollably into the back of another HGV."

The driver of the other HGV, Jason Lear, who was travelling from Wellingborough to Diss in Norfolk, said he saw the collision with the caravan.

He added: "Debris was being flown everywhere."

Michael Kisby, who was driving a silver BMW 318 at the time, said: "The Mercedes Sprinter van leapt into the air and hit my car and went into the lorry in front."

The road was closed for 10 hours while the accident was cleared.

Coombes is accused of death by dangerous driving but denies the charge.

The case continues, with expert witnesses due to address the court today.