HORRIFIED onlookers watched in terror as the lorry, loaded with bricks, careered down Crendon Street and across Easton Street straight through the front window of Aitchisons Estate Agents.

The driver, 37, is thought to have lost control as it came down the hill with the horn sounding. Its brakes may have failed causing it to smash into several cars in Crendon Street before the tragic crash.

Emergency services were unable to save the lives of Maggie Doel and Sally Jamieson who were in the building at the time, along with Royston Davis who escaped unharmed.

Four injured people were taken to Wycombe Hospital including the lorry driver who suffered a head wound and was pulled from the wreckage.

A pedestrian, who is believed to have jumped out of the way, suffered a leg wound and two men were described as walking wounded. None of them were thought to be seriously injured but were said to be suffering from shock.

Ritchie Carroll, of Gerrards Cross, was just yards away when the accident happened.

He said: "I just saw a van spin round the corner and heard the man driving the lorry beeping his horn. The van was knocked out of the way and the lorry just smashed straight into the estate agents. I have never seen anything like it. People were screaming but I don't even remember where it was coming from."

Dave Bisco, of Elm Road, High Wycombe, who was parking his car near the library at the time, added: "The road is just not big enough for articulated lorries."

Police are expecting months of investigation into the incident.

Amersham traffic PC Andy Wayland, who was called to the scene, said: "We are examining, among other possibilities, that the brakes may have failed. I came down just after the crash and there was debris everywhere and just an eerie silence."

Firefighters from High Wycombe Fire Station were on the scene within a few minutes and immediately called for backup.

Station Officer Graham Field, based at High Wycombe, said: "From there, it was a case of trying to create some kind of order, working with ambulance and police crews, making the area safe." He added the crew realised people had died in the crash but used their training to carry on working on releasing the crash victims.

It took fire fighters in excess of 40 minutes to free trapped people. The last person was released by 3.40pm but fire crews stayed on the scene until 9pm in case of a fire or if the building collapsed.

Structural engineers from Wycombe District Council were called to the scene, as well as gas and electricity engineers. Roads around the junction were cordoned off until around 10pm.

The driver of the lorry, from Bedfordshire, was arrested and later released on police bail.

Witnesses should call PC Gerry Byrne on 01494 465888.

More coverage in the Bucks Free Press on Friday