Five teenagers from the same high school have died after a single-vehicle crash south-west of Sydney.
Emergency services were called to East Parade in Buxton, near Picton, just before 8pm on Tuesday following reports a utility had left the road, rolled over and struck a tree.
Police say the driver, an 18-year-old man, has been taken to Liverpool Hospital with non-life threatening injuries.
Police have confirmed that two girls aged 14 and one aged 15, as well as boys aged 15 and 16, died in the crash.
Wollondilly Mayor Matt Gould said the teenagers all attended Picton High school and everyone in the local community was mourning.
"The entire community is numb and in shock. We're a very close community, especially Buxton.
The ABC understands at least three of the victims were in year 9.
Superintendent Paul Fuller said it was too soon to know the cause of the crash but the scene was "horrific".
"A traumatic event like this will have a devastating impact on the families, friends and the local community," he said.
"It's just heartbreaking."
He said the driver of the car was arrested for the purposes of mandatory testing for drug and alcohol via urine samples.
He has not been charged.
Murat Dizdar from the NSW Department of Education said there would be two separate counselling teams onsite at Picton High School today.
"One is for staff that may be impacted by this news. And the other team is for students. They'll be able to provide expert specialist care for any staff or student who is impacted by this news," he said.
"We will also be working with surrounding primary schools because, unfortunately, the deceased may well have siblings that are enrolled in our primary schools."
Superintendent Fuller said it was one of the worst crash scenes he had seen in 38 years as a police officer, and losses would be felt heavily by the small local community.
"Unfortunately some of the first responders would know these kids," he said.
"Look some of these kids are 14, 15, can I just say to parents, know where your kids are."
Vision from the area shows emergency services around a car, which appears to have hit a tree.
Fire and Rescue NSW Superintendent Adam Dewberry said emergency services were called to the scene in Buxton where they found a scene of devastation.
"Unfortunately it was evident pretty early what the outcomes were," he said.
"All of the emergency services, police, ambulance, [were] confronted with a significant, critical, traumatic scene.
"It was absolutely chaos and devastating."
He said responding emergency service personnel will be provided with support.
Crash investigators are on the ground at the village in the Wollondilly Shire, which is about 100 kilometres south-west of Sydney.
A report will be prepared for the information of the Coroner.
