A private bus driver mounted a kerb when he realised that the brakes on his vehicle had failed, to avoid a crash with the stationary cars in his path. But he hit a woman cycling home from work on the footway along Pioneer Road North.

An inquiry yesterday into the death of Madam Wong Lai Cheng, 48, on Jan 12 found that the brake failure on the bus, driven by Indian national Kannan Murugavel, was due to a missing drain valve component.

State Coroner Marvin Bay said a vehicle inspection had found air leaking from the defective tank from which the valve was missing.

Sufficient air pressure needed to operate the brakes could not be built up. As a result, the bus had no braking ability whatsoever.

Finding Madam Wong's death to be a "tragic traffic misadventure", Coroner Bay said the trail of destruction included damage to five vehicles and uprooted signs and trees, showing the catastrophic consequences of brake failure in a heavy vehicle.

He added: "The sad circumstances of this case underscore the fundamental importance of scrupulous and conscientious maintenance of heavy vehicles to prevent or mitigate the risk of failure of crucial component parts such as their braking systems.

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MAINTENANCE ESSENTIAL The sad circumstances of this case underscore the fundamental importance of scrupulous and conscientious maintenance of heavy vehicles to prevent or mitigate the risk of failure of crucial component parts such as their braking systems. It may also be helpful for heavy vehicle drivers to acquire defensive driving skills to be able to anticipate and handle exigencies... STATE CORONER MARVIN BAY, who said a vehicle inspection had found air leaking from a defective tank, affecting the brakes of the bus.

"It may also be helpful for heavy vehicle drivers to acquire defensive driving skills to be able to anticipate and handle exigencies...so as to be able to operate and manoeuvre their vehicles in a manner that is least likely to cause injuries to themselves and other road users or property damage ."

Earlier news reports stated Mr Kannan, 29, had been working for Johnson Transport and Trading for about two months before the tragedy. Before that, he had driven a lorry for nine years with another Singapore company.

It was also reported that he was driving from Lot One Shoppers' Mall in Choa Chu Kang to pick up workers from a shipyard and no passengers were on board.

According to yesterday's findings, he was driving along the Pan-Island Expressway towards Benoi Road when he heard a loud noise from the rear of the bus. Suspecting that a tyre had punctured, he made an exit into Pioneer Road North.

While on the slip road, he realised that his brakes were not working.

Noticing there were stationary vehicles ahead, Mr Kannan decided to manoeuvre his vehicle into a nearby tree to stop the bus from ploughing into them.

Coroner Bay said: "While it is clear that Mr Kannan's act of mounting the kerb was a deliberate action, this appeared to have been done in the agony of the moment as he was attempting a controlled crash to stop the vehicle.

"Mr Kannan appeared to have been unaware that his execution of the manoeuvre would have brought him into a collision course with Madam Wong... until it was too late."

The bus hit Madam Wong, who worked as a hall operations assistant at Nanyang Technological University. She was then dragged under the vehicle as it careened forward.

The bus knocked over a zebra crossing pole and hit two trees and the other vehicles before coming to a stop 41m away from where it had mounted the kerb.

Madam Wong, who suffered severe head injuries and a ruptured liver, was pronounced dead at the scene at 6.20pm.