Three people aged 18,19 and 20 have died and three others remain in hospital following a head-on collision on Bells Line of Road in Bilpin at 3.30pm yesterday.
A Mitsubishi SUV and a Subaru sedan were involved in the accident which took place about 500 metres east of the Fruit Bowl on the brand new overtaking section of the road.
The driver and front passenger of the Mitsubishi were taken to Westmead hospital with back and neck pain, however the three passengers died on the scene.
All the Mitsubishi's male occupants are believed to be from the Northern Beaches.
The driver of the Subaru, an 85-year-old Colo Heights resident, was airlifted to Westmead Hospital in a serious condition due to her age.
She suffered a broken ankle and remains in hospital where she will have CT scans and be further assessed by doctors.
Bells Line of Road was closed in both directions for more than seven hours with police, paramedics, Bilpin Rural Fire Service volunteers and Hawkesbury SES volunteers on scene.
It is believed she was driving back home from a 60th birthday party.
Bilpin resident John Bryant said she is well known in the Hawkesbury and many people will be upset about her condition.
He added she is lovely, giving and a selfless person and hopes she has a speedy recovery.
An announcement of her accident was made at the Hawkesbury Valley Baptist Church yesterday evening where she is a member.
The Traffic and Highway Command Accident and Investigation squad will continue to investigate the cause of the accident.
Anyone who witnessed the accident and hasn’t yet spoken to police are urged to contact investigators.
A report will be prepared for the Coroner.
Initial Triple Zero reports said the accident had taken place in Kurmond and the Gazette received those first reports from NSW Police Media.
Meanwhile, police are urging motorists to take extra care on the roads as part of Operation Saturation which began midnight on Thursday and will run until September 28.
As part of the operation, officers will target unsafe driving behaviour like speeding, drink and drug driving, mobile phone use, fatigue and seat belt offences.
They will also pay particular attention to improving safety for vulnerable road users, especially pedestrians, older people and motorcyclists.