She was due to celebrate her Chinese birthday on Wednesday.
Madam Lim Ah Moi, 78, had looked forward to ushering in the new year with her family on a good note.
But on New Year's Eve, she died after an accident between a taxi and a car she was in on Lentor Avenue, near the Seletar Expressway exit.
Three ambulances were used to take all the casualties to the hospital, said the Singapore Civil Defence Force.
Seven other casualties, including Madam Lim's grandson and their maid, who were also in the car, were taken to Khoo Teck Puat Hospital (KTPH).
Madam Lim died from her injuries at KTPH, said a police spokesman.
It has been two days after the accident and the family is still recovering from the shock.
Mr Edmund Oh, her third son, told The New Paper on Sunday in Mandarin: "She had plans for a birthday party with us but there is no point now. I still cannot believe this happened."
Madam Lim had been feeling feverish and the clinic that she frequented was closed.
It was Mr Oh's son who asked to take her to the hospital with a friend's car.
Mr Oh, who was at work when the accident happened, said: "I called my son to ask if they had reached but I couldn't get through. I thought they were caught in a traffic jam.
"I was absolutely shocked when the hospital called me to say they had been in an accident and my mother had died."
Mr Oh's son, whose right leg is injured and has to use a wheelchair, declined to be interviewed.
The family was travelling on Lentor Avenue while the taxi was turning when the accident happened, he told Chinese newspaper Shin Min Daily News.
The older Mr Oh told TNPS that the impact to the front left of the car was very hard.
He said: "I just don't understand how this could have happened. The taxi must have been moving quickly because the car ended up on the kerb."
The family is waiting for answers from the ongoing police investigation before deciding their next step.
Mr Oh said his son remains affected by the incident. "He feels really bad," he added.
Madam Lim was the matriarch of the Oh family that runs the Pin Si and Gim Tim brands of restaurants. The Oh's also run GT Food Supply, a catering business.
TNPS visited the wake in Yishun last night.
More than 300 funeral wreaths and sympathy blankets from friends, colleagues and business partners lined the void deck of Madam Lim's block.
The funeral will be held tomorrow afternoon.
This article was first published on Jan 3, 2015.
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