An SMRT taxi driver who lost consciousness behind the wheel ploughed into pedestrians in Queenstown on Friday evening, resulting in the death of a 66-year-old woman.
Two others, including the 72-year-old driver, were injured in the accident at the junction of Jalan Bukit Merah and Alexandra Road, the police said yesterday.
The police, who were alerted at about 7pm, said the driver and two women, aged 32 and 66, were taken to the National University Hospital.
The older woman later succumbed to her injuries at the hospital, they said.
Preliminary investigations revealed that the taxi driver had lost consciousness prior to the accident. He is currently assisting in police investigations.
A video posted on Facebook page SG Road Vigilante on Friday night shows the taxi driver running the red light and abruptly making a right turn, crossing the path of vehicles that were heading straight.
Dashboard camera footage from another angle then shows that the taxi's hazard lights were switched on and the vehicle changed lanes before making the turn.
Several pedestrians were seen crossing the road when the taxi crashed into them.
A woman was later pictured lying on a stretcher on the road as paramedics attended to her.
SMRT said its immediate priority was to try to get in touch with all affected families to render assistance and support. The transport operator is also cooperating with the police in their investigations.
A witness, identified only as Ms Wang, told Chinese-language evening daily Shin Min Daily News the taxi collided into two women.
One of them landed on a grass patch and had head and arm abrasions. After she came to, she hurried over to comfort her son, who saw the accident and was crying loudly.
Chinese-language daily Lianhe Wanbao reported that photos from a witness named Ms Chen showed that the other injured woman, who was lying on the road, was bleeding from her mouth and nose, and appeared to be unconscious.
Earlier this month, a ComfortDelGro taxi driver fainted while driving on the East Coast Parkway and collided with a centre divider. His passenger then alighted in the middle of the expressway.
ComfortDelGro said then that the cabby had "blacked out momentarily", and when the driver regained consciousness, he realised that his passenger had disembarked.
Emergency physician Charles Johnson told The Sunday Times that a sudden loss of consciousness is usually related to the heart or the brain, such as an abnormal heartbeat, a stroke or a seizure, or a fall in blood pressure that decreases blood flow to the brain.
Some of the causes can be prevented, such as those that occur when diabetics do not take their medication and black out because their blood sugar levels drop.
But there are non-preventable causes such as having a stroke, Dr Johnson said.
He said falling asleep for a short period - as short as a split second - without even realising it while behind the wheel can be life-threatening, too.
This could happen if a person was tired, took medication that causes drowsiness or was under the influence of alcohol, which affects the driver's concentration.
Dr Goh E Shaun, an emergency medicine specialist at Raffles Hospital's accident and emergency department, said that it is important to get enough sleep and rest prior to any long road trip.
Once fatigue sets in while on the road, it is important to take a break when convenient, he added.