Four young lives lost after driver hits tree near Hamilton in western ...

Police say four young people killed in a single-car crash in Victoria's west were likely teenagers from the area, as an investigation into the "horrific" crash continues.

Key points:Police believe the driver of the car lost control before hitting a tree on a quiet road near HamiltonFour people died at the scene and a fifth teenage girl is in a critical conditionPolice say the crash will unleash profound trauma on the "close-knit" community

Sergeant Ryan Nelson said police believed the driver of a sedan carrying five teenagers, all of whom were female, lost control of the car as she drove along Wannon-Nigretta Road near Hamilton and hit a tree.

Emergency crews were called to the crash around 9:30am Saturday, but were unable to save the lives of four people who died at the scene.

A fifth teenager was flown to the Alfred Hospital in Melbourne in a critical condition suffering upper body injuries.

"The scene is still pretty horrific at the moment," Sergeant Nelson said on Saturday night.

Police believe those who were killed were from the local community around Hamilton.(ABC News)

"Hamilton's a very close-knit community and there's five people involved in this and all their families and all their friends.

"It's going to hit the town really hard."

Major Collision Investigation Unit detectives cordoned off the scene on Saturday and began what Sergeant Nelson said would be a full investigation to bring answers to grieving families.

Police are running an extensive investigation into the cause of the deadly crash.(ABC News)

The crash occurred on a relatively quiet, rural road which runs past Hamilton Airport and the tourist attraction Nigretta Falls.

"It is a quiet road, but it is a 100-kilometre zone and we're still making inquiries into how this happened," Sergeant Nelson said.

There have been 124 lives lost on Victoria's roads this year, according to the state's provisional tally, compared to 96 lives at the same time last year.