City Audi workers have told of their miraculous escape after a massive steel beam snapped in two and caused their building to collapse before their eyes.
Employers, thinking an HGV had crashed into them, evacuated the ten-month-old premises as soon as they heard the warning crack.
Minutes later they watched in horror as the walls of the £7 million building bulged out before the rooftop car park collapsed, sending 20 cars crashing down.
Among the witnesses was VIP visitor Mark Herbert, national chief executive of Jardine Motors Group which runs the dealership.
“Like everybody, Mr Herbert stayed calm. We all just stood there open mouthed, watching the building collapse in what seemed like slow motion,” said one employee.
“Through the windows we could see the roof and the cars crashing down, landing on top of each other. At that stage we were worried about fuel leaking out and causing an explosion,” he added.
“We could also see the 12 inch gap in the steel beam where it had snapped.”
Monday was stocktaking day and workers had been up and down the outside ramp to the roof area checking the trade in vehicles and small number of brand new Audis parked there.
There is no suggestion that the roof was overloaded with cars.
One employee said: “I’d walked up the ramp shortly before the collapse. If it had happened minutes earlier I could have been killed. We all feel extremely lucky to have come out unscathed.”
While emergency services dealt with the chaos, the 60 staff were evacuated along Northfield Drive to the nearby BMW building - which is also owned by the company.
They are now working from BMW offices while experts, including Milton Keynes council building control officials, examine the wreckage to discover what happened.
The new headquarters was built by Sheffield company BDB Design Build Ltd and completed in August last year. BDB senior staff travelled to the site on Monday as soon as news of the incident broke.
Meanwhile a spokesman for Jardine Motors Group said: “Clearly the wellbeing of our staff and customers is our utmost priority at this time and we will work tirelessly to ensure that normal business will resume slowly.”