Posted by 
Two adults have died and a nine-year-old girl is among five people in a critical condition after a horror crash in the NSW Central Tablelands.
More than 80 emergency services professionals were called to the Great Western Highway at Wallerawang, about 15 kilometres north of Lithgow, after five cars collided just before 1pm today.
Two people died at the scene and about 15 others, including several children, were treated for a range of injuries.
READ MORE: Queensland town's water supply at 'critical low'
9News understands this included a nine-year-old girl who was flown to The Children's Hospital at Westmead with critical head and chest injuries.
Wreckage and debris were scattered across hundreds of metres, including a four-wheel drive thrown off the road and into bushes.
A car towing a caravan entangled with a motorbike trailer, snapped from the back of a ute and packed bags and pillows were also found at the scene.
The Great Western Highway remained closed in both directions at 7pm.
Police said it would remain a crime scene for a considerable amount of time but it was hoped the road would be cleared by 10pm.
"We would be appealing for members of the public perhaps that were in the area that either witnessed the collision or dashcam footage," NSW Police Superintendent Paul Glinn said.
He said a police investigation into the cause of the crash was in its "infancy".
"There was one lane eastbound, two lanes westbound it would appear that a vehicle has crossed to the incorrect side of the road," he said.
Declan Jones, 19, and family friend Jason MacMahon had just finished a day of dirt bike riding at Sunny Corner and were travelling home to western Sydney when they were caught up in the crash.
Two other young people, including a 15-year-old girl with abdominal injuries and an 11-year-old girl with abdominal and head injuries, were also flown to Westmead.
It is understood a five-year-old girl with broken ankles was also airlifted to hospital with her mum.
Four other children received medical attention for minor injuries.
A 50-year-old man was flown to John Hunter Hospital in Newcastle with abdominal and leg injuries.
Two women were taken to Orange Base Hospital, including a 40-year-old with spinal injuries and a 35-year-old woman with leg injuries.
Paramedics drove three people with minor injuries to Nepean Hospital.
READ MORE: Woman charged with targeting mailboxes over festive season in Sydney's west
NSW Ambulance acting Superintendent for the Nepean Blue Mountains area Emily Stevens said 23 road crews and four helicopters were sent to the scene.
"Due to the number of casualties, we had to respond to a number of hospitals around the state," she said.
"Our road crews responded from a very wide range, the longest being from the Penrith Nepean Blue Mountains area.
"Our helicopter crews responded from Wollongong, Newcastle (and) all around the state as well."
Glinn said the scene was significant from a police perspective.
"We had in the vicinity of upwards of 80 rescue personnel here, that's from both the ambulance, Fire and Rescue, Rural Fire Service, the Volunteer Rescue Association, SES and others," he said.
"We do thank everyone for coming together to provide the best outcome for those people who were injured and those people who witnessed the collision."
Fire and Rescue NSW Duty Commander Phil Vaiciurgis said initial firefighting crews arrived at "a confronting scene of carnage".
"Crews with the assistance of ambulance and volunteer rescue association had to make critical decisions triaging patients," he said.
"We had to do two complicated rescues from severe entrapment injuries, and provide fire protection and assist police and ambulance rendering the scene safe," he said.
Glinn reminded drivers to consider the safety messages around this time of year.
"There's a lot of people on holidays, there's a lot of people travelling on roads, so we just remind people to drive to the conditions and slow down," he said.
"Every time you get behind the wheel, you need to make good decisions and ultimately you're responsible for what occurs to ensure the safety of yourself and your passengers.
"There's lots of people and others out and about on the roads.
