THIS month marks the 30-year anniversary of the Greenmount Hill truck disaster, which saw one killed, 12 injured, and 20 cars crushed, and became the largest motor vehicle crash in the state that year.

On December 30, 1993, at 9.45am a fully laden 20-tonne wheat truck, towing a 20-tonne trailer of grain, screamed down Greenmount Hill on Great Eastern Highway.

The driver of the Scania truck had reportedly lost control due to a mechanical failure and had ploughed through six vehicles part way down the steep three-kilometre long slope.

The truck continued another 1.5km before it ploughed through the Roe Highway intersection where it hit 14 more vehicles.

The manager of a caravan dealership at the intersection, Barry Garner, who witnessed the crash said the truck sheared its front axle once it hit the median strip at the intersection.

“The trailer then flipped on its side and crashed through a line of seven vehicles waiting at the lights,’’ he said.

“It took the top off three cars. The place looked like a battlefield.”

A 20-year-old woman was killed, 12 people were injured, four of them seriously, and seven people had to be cut free by firefighters, while the driver suffered minor injuries.

Wreckage and wheat were strewn over 300m and the intersection remained closed for five hours.

The Greenmount Hill arrester bed was installed in the years following the 1993 trucking disaster and has been used several times since.

The most notable recent use was in 2012, when a bus carrying over 40 asylum seekers lost control on its way down the hill, but fortunately no one was injured.