A car crash early yesterday morning killed the 33-year-old mother of a family of four, and injured her husband and two children.
The accident occurred at about 1.15am at the junction of Lentor Avenue towards Ang Mo Kio Avenue 6, police said.
The deceased, believed to be a Ms Sim Yee Ling, was travelling with her husband Simon Tan and their two sons, aged three and six, when their white Honda sedan crashed into a tree.
She was pronounced dead by paramedics at the scene, and her husband has been arrested for causing death by a rash act.
It is believed that Tan, 42, who was behind the wheel, lost control of the vehicle before it skidded left and crashed into a tree.
Ms Sim was in the back seat with her younger son at the time, a witness told Chinese evening daily Lianhe Wanbao.
She was flung to the front by the impact and hit her head on the handbrake.
It is not clear if the passengers were wearing their seatbelts when the accident happened.
The impact crushed the car's bonnet and shattered the windscreen. Its rear bumper was also dislodged.
A Singapore Civil Defence Force (SCDF) spokesman said it sent two fire engines, three ambulances and one support vehicle to the scene.
Tan, who complained of drowsiness, was taken conscious to Khoo Teck Puat Hospital.
The Straits Times understands that he suffered a brain haemorrhage and has been warded in the intensive care unit.
The two boys were conscious when they were taken to KK Women's and Children's Hospital, the SCDF said.
A taxi driver, who was at the scene, said both boys were crying for their mother.
Tan Yu Sen sustained spinal injuries, while his younger brother Wei Quan suffered serious injuries to the head, and is believed to be in the intensive care unit.
Ms Sim's Facebook page shows several photos of her and her sons on outings to places such as Sentosa. In a post in October 2011, Ms Sim had called her husband her "one and only".
In a later post, written in Mandarin, she asked her friends to give their blessings to her and Tan.
Ms Sim was born in Ipoh, Malaysia, and married Tan in 2012.
More than 10 motorists stopped to help after the accident, Lianhe Wanbao reported.
Some deflated the car's airbag and pulled the driver out from the wreckage while others directed traffic and comforted the boys.
Investigations into the accident are ongoing.