THE M40 was closed for nearly six hours yesterday after three people were killed in a seven-car smash.

Traffic was backed up in all directions for more than five miles as emergency services worked at the scene on the London-bound Loudwater flyover.

Both carriageways were shut between junctions three and four and the slip road at junction two was also closed soon after the smash, which happened at around 10.40am.

Buckinghamshire County Council advised motorists to avoid High Wycombe for the whole day as tailback traffic was re-directed through the town.

The M40 was due to be re-opened at 4.30pm as we went to press.

Two men and a woman were pronounced dead at the scene, two of them had been travelling in the lorry. Two children were among 11 people who were also injured.

Police believe the pile-up was caused when a lorry driving towards Oxford crossed the central reservation and hit the traffic travelling southbound.

A further three vans and three cars were involved in the crash.

All the injured were taken to Wexham Park Hospital in Slough and four had to be transported on spinal boards.

Their injuries were believed to be non-life threatening and the other seven patients were described as walking wounded.

Fire crews called to the scene had to cut through the central reservation so ambulances could get people to hospital.

Staff at bedroom store Dreams in Knaves Beech business park, Loudwater witnessed the smash from the window of their headquarters boardroom during a meeting.

They described hearing "a loud explosion" and saw a massive cloud of grey and black smoke billowing from a mass of mangled metal. One said the impact of the crash made the building shake.

Another said: "It's just awful to think what everyone's going through up there. It's horrific, obviously being on the M40 we see accidents happening around that area, but there's never been one to that extent.

"I think it's shaken up quite a lot of people in the office."

Firefighters could be seen on the flyover covering the lorry with a tarpaulin and working at the scene.

Edward Clare, assistant manager in Dreams showroom, saw debris from the crash rain down onto Knaves Beech Way, underneath the flyover.

He said: "We heard a big screech and then several crashes. We went outside and saw debris come off the flyover onto the road. We were serving customers as well so it was very scary.

"We saw the lorries, one had a load of pallets on it and it looked like a man was stuck in it and they were trying to get him out. One of them I can see up there now, it's completely in shreds."

An air ambulance was called to the scene along with four land ambulances, three fire crews from High Wycombe and Beaconsfield, and police.

Officers are now appealing for witnesses to the crash to get in touch.

Inspector Steve Bridges, investigating the collision, said yesterday: "Collision investigators are on scene working to establish the cause of the collision.

"We are especially interested in anyone who saw a white flatbed lorry loaded with blue pallets travelling northbound from the M25 to junction three at High Wycombe."

Call police on 08458 505 505 or anonymously through Crimestoppers on 0800 555 111.