A coroner's inquiry found that the driver of a prime mover had been speeding, and a punctured tyre sent the vehicle out of control, flinging passenger Nurul Nabilah Zubri, 12, out of the vehicle.
She died later in hospital.
State Coroner Victor Yeo said it was unlikely the vehicle had been travelling at between 50 and 55 kmh, as the driver Mohamad Zubri Samat, 39, had testified. He is the dead girl’s father.
The accident happened in November last year.
Calculations by accident reconstruction experts of the 28m-long skid marks at the accident scene showed that the vehicle had been going faster than its 60 kmh speed limit.
Coroner Yeo also noted that Nurul Nabilah had not had any seat belt to wear, as she had been seated between the passenger’s and the driver’s seats.
Although only two persons were permitted to be in the cabin, there were five that day.
They included Nurul Nabilah’s youngest sister, then eight months old, who was on her mother’s lap; and her 11-year-old sister, seated in an empty space behind the seats.
Mr Mohamad Zubri told the inquiry that the family had been on their way from Bedok to visit his mother in Bukit Batok for Hari Raya Haji.
He was driving on the extreme left lane near Paya Lebar at about 55 kmh when he heard an explosion at the front right tyre.
The vehicle then veered right into the central divider and only came to a stop near the grass verge of the expressway headed towards Changi Airport.
He said he had been unable to control the prime mover as the steering wheel was “stuck”.
He added that he did not see Nurul Nabilah being flung out, but saw her lying injured in the centre lane behind them moments later.
She died of multiple injuries after she arrived at Changi General Hospital.
Her parents suffered leg fractures, while her two sisters had minor injuries.
Only Mr Mohamad Zubri was in court yesterday.
The accident had left him with a noticeable limp. The other family members have since recovered fully.
The case has thrown the spotlight on drivers of prime movers, who require a Class 4 or Class 5 licence to drive these heavier vehicles.
In the first six months of this year, about 2,200 summonses have been issued to heavy vehicle drivers, up from 1,500 in the same period last year, said a police spokesman yesterday.
Prime movers, tipper trucks and trailers were involved in 123 accidents from January to June this year, up from 114 accidents in the same period last year.
The number of summonses issued for offences such as speeding and careless driving by heavy vehicles has increased from 3,394 in 2009 to 3,544 last year.
Singapore Safety Driving Centre assistant manager Gerard Pereira yesterday cautioned drivers of heavy vehicles against speeding.
“Class 4 vehicles often carry multi-tonne loads and this makes sudden braking very dangerous,” he said.
Referring to the case, he added that passengers in the driver’s cabin are required to wear seat belts at all times.
The Land Transport Authority (LTA) said the number of front passengers permitted in a prime mover cabin is determined by its licensed passenger capacity.
The police added that child booster seats must be used if passengers are below eight years of age.
The court heard that although the tyres of the prime mover Mr Mohamad Zubri was driving had been replaced seven months before the incident, the left front tyre was not roadworthy as it had a cut longer than 25mm and the internal structure was exposed.
A check of the burst tyre revealed its inner side wall blew apart, very likely before the accident.
There were also no signs that it had been caused by an object the tyre had come into contact with.
However, there was nothing wrong with the engine, brakes and steering.
Heavy vehicle transport companies told The Straits Times that the onus is on the driver to ensure that vehicles are roadworthy.
Mr Toh Kim Chuan, who owns Kim Chuan Transport, said: “Our drivers have to perform safety checks on the vehicle before they move out for jobs each time.”
LTA regulations stipulate that goods vehicles like prime movers are required to be inspected annually until they are 10 years old.
Those over 10 years old are to be inspected every six months.
Vehicles that fail the periodic inspections would have to be sent for repairs before re-inspection.
