The truck’s Wodonga driver was hospitalised, while the occupants of three cars that slammed into a gum tree brought down in the incident were able to walk away, shaken but unhurt.

The truck driver has head injuries and broken ribs and was last night in a stable condition in Wangaratta Hospital.

Sgt Michael Connors, from Wangaratta highway patrol, said police had not been able to quiz the driver on the incident but noted speed didn’t appear to be a factor.

The crash happened about 6.30am when the 20-tonne truck, travelling north, veered onto the median strip and hit a tree and bridge before plummeting down a five- to six-metre drop into Webb Creek, about five kilometres from the Wangaratta exit.

In the pre-dawn dark, three cars travelling in the southbound lane and driven by an Albury man, 63, Lavington man, 62 and a couple from Wedderburn were unable to see the tree in time to stop.

Another 20 vehicles behind them were trapped for 90 minutes before being allowed to pass the scene.

Police closed the southbound lanes of the highway for four hours as they diverted traffic through Wangaratta.

The EPA was also called to the scene but a spokeswoman said a minor spill of diesel and oil was contained by the CFA.

Last night vegetables were being unloaded from the truck, which belongs to Wodonga company Cubtrans Express, in preparation for it to be lifted out of the creek.

It is a procedure that is expected to require the southbound side of the freeway to be closed from the Bowser interchange, at the north Wangaratta exit, from daylight this morning until lunchtime.

Sgt Connors said while he had seen plenty of trucks run off the road, this crash posed a challenge for emergency services. 

Salvage experts were yesterday called in to work out how they would be able to winch the truck from the muddy water.

The truck’s owner was last night unwilling to comment on the incident.