Stevens told reporters this afternoon that SA Police had deployed a traffic management expert, a planning expert and a senior police officer to the Bordertown checkpoint today to conduct a safety assessment.

He said he had also launched a “commissioner’s inquiry” to “examine the circumstances in regards to how we’ve been managing our border checkpoints”.

It follows a serious crash involving three trucks five-kilometres east of the SA border about 2am, soon after SA authorities shut the border to greater Melbourne at midnight, prompting a surge of traffic trying to enter SA before the deadline.

Police said a truck drove into the rear of another truck that was stopped in a queue of vehicles, and that truck in turn smashed into a third truck ahead of it.

All three trucks burst into flames. The collision killed one truck driver, with two others in a stable condition in hospital.

Stevens described the incident as “incredibly sad”, but refused to say whether the conditions at the checkpoint contributed to the driver’s death.

“I think we should conduct our inquiries and provide factual information based on the information that we’re able to obtain and be clear in our assessment as to what the circumstances were,” he said.

“I wouldn’t be called on whether or not the arrangements in place were adequate or not, but I have ensured that we will do a proper inquiry alongside the work being done by Victoria Police to provide a factual assessment of exactly what’s transpired and what the causative factors were.”

Stevens said five police officers were deployed to the checkpoint during the day, but that number was decreased to three during the evening.

He said there were “relatively low levels of activity” at the checkpoint up until 9.30 at night.

He said a further two police officers were deployed to the checkpoint once vehicles started to build-up.

While the collision took place in Victoria, Stevens said SA Police managed the checkpoint signage leading into the checkpoint “which means that we are stepping into that side of the border”.

He added that “any loss of life on our roads is a tragedy that impacts on so many people”.

“This truck driver’s family are now grieving, the people he works for, his colleagues are all experiencing significant loss – there’s no doubt about that,” he said.

“These border checkpoints are put in place to protect the South Australian community, both from a physical health point of view as well as an economic and social perspective as well.

“It’s incredibly sad that someone’s lost their life in these circumstances – I don’t know there’s much more you can say about that.”

Premier Steven Marshall and chief public health officer Professor Nicola Spurrier extended their condolences to the truck driver’s family.

It comes as South Australian authorities announced they would remove testing requirements for travellers from New South Wales and Western Australia from midnight Saturday.

But anyone who travels into South Australia who has COVID-19 symptoms should immediately self-isolate and get tested.

Marshall said South Australia’s festival season was on schedule to run as planned, despite the border restrictions with greater Melbourne.

Spurrier said South Australia might not need to wait two weeks before lifting the restrictions.

“In this instance, because it’s just happened, we’re in the early stages and we may not need to wait a whole two weeks,” she said.

“It’s too early to say how long we’ll have that border shut for – it will really depend on how things go over the next couple of days.

“I’m feeling relatively confident as we get more and more information from Victoria that I’m hopeful that this will settle down.”

Victoria’s Holiday Inn quarantine outbreak hit double figures this afternoon, with two household contacts of infected workers testing positive for COVID-19.

The Victorian Department of Health reported the two new infections were linked to the hotel at Melbourne Airport.

They are both household primary close contacts of previously confirmed Holiday Inn staff cases.

The outbreak now stands at 10 and includes three workers, two primary household close contacts, two released guests and a family of three who contracted the virus overseas.

-with AAP