ONE person is dead and another is critically ill after a collision on the Western Highway at Lawloit.
Police advise the highway will be closed to all traffic until later in the morning.
A tray truck was heading east and a B-double truck was heading west when they collided head-on at 1.45am.
The tray truck driver, a Melbourne man aged about 45, died at the scene.
Horsham Acting Sergeant Tony Sykes said the other driver, believed to be a man in his 50s, was taken via air-ambulance to a Melbourne hospital.
He said the driver had chest injuries that were life-threatening.
The Royal Melbourne Hospital confirmed the man was critically ill.
Acting Sgt Sykes said there appeared to be no witnesses but a truck had driven past shortly after the crash.
He asked anyone with any information to call Crime Stoppers on 1800 333 000.
Acting Sgt Sykes said Kaniva and Nhill police, along with State Emergency Service, ambulance, and Country Fire Authority attended the crash.
The cause of the crash is yet to be established.
Traffic is being diverted between Kaniva and Horsham via the Wimmera Highway and Kaniva-Edenhope Road.