Former national rugby player Slemat Rakisan was thrown off his motorcycle after it was hit by a stray tyre on Kranji Expressway more than two years ago.
The 57-year-old was pronounced dead at the scene by paramedics in the incident on March 16, 2017. The tyre was found to be one of two that had been dislodged from a prime mover.
Yesterday, State Coroner Kamala Ponnampalam ruled Mr Slemat's death as an unfortunate traffic misadventure.
She said in the inquiry into his death: "Prior to the accident, the prime mover had been poorly maintained... causing the two wheels to fly off the wheel axle and one of them to strike Mr Slemat as he was travelling on his motorcycle."
Experts found that the prime mover was "not in road-worthy condition", she added.
Investigations revealed that the two rear left tyres had become dislodged as the driver was travelling along an upward slope.
Prior to the accident, the prime mover had been poorly maintained... causing the two wheels to fly off the wheel axle and one of them to strike Mr Slemat as he was travelling on his motorcycle.
STATE CORONER KAMALA PONNAMPALAM
The driver saw the tyres rolling off the prime mover, with one rolling to the left and the other to the right towards the centre divider. The tyre bounced off the centre divider and flew towards Mr Slemat, causing him to lose control of his motorcycle and to skid and fall.
Subsequent mechanical inspection showed the prime mover's wheel-rim stud holes - for mounting the tyre to a vehicle's axle - were badly worn.
There were also signs of improper securing and tightening of the wheel studs and wheel nuts. This caused the rotating left wheels to detach from the axle.
Tributes from members of the rugby fraternity poured in following Mr Slemat's death. He left behind his wife and three grown-up children.