Stoneleigh highway horror: Two children and one adult are killed after their car was crushed by a truck on a busy motorway

Two children and an adult have been killed after their car was crushed by a truck.

Emergency services rushed to the intersection of Eurambeen-Streatham and Mount William roads in Stoneleigh, 200km from Melbourne, about 9.30am on Tuesday.

Victoria Police said a car carrying two adults and two children rolled and was crushed by a truck on a major motorway.

One of the adults and the two children died at the scene.

The other adult, who was trapped in the vehicle, suffered life-threatening injuries and is expected to be airlifted to hospital.

The truck driver is understood to have sustained minor injuries.

Authorities have cordoned off the area. The surrounding roads are blocked while members of police and emergency services respond to the incident.

Anyone who witnessed the incident or has dashcam vision has been urged to contact Crime Stoppers on 1800 333 000.

According to data from Victoria Police, 247 lives have been lost on roads so far this year, including 18 children.

Last year, 241 people died on Victorian roads up to November.

Stoneleigh, which is about 45 minutes from Ballarat, is a small town with a population of 45 people.