A truck was travelling at 100kmh on a Melbourne freeway when it hit and killed four police officers dealing with a driver who had tested positive to a roadside drug test.
Flags will fly at half-mast across Victoria on Thursday in honour of the officers who died when the truck ploughed into them as they stood on the Eastern Freeway at Kew about 4.50pm on Wednesday.
Further details about the female senior constable, male senior constable and two male constables, one of whom only recently joined the force, are expected to be released later on Thursday.
Two of the officers pulled over the black Porsche 911 after they clocked it speeding at 140kmh on the freeway.
The driver tested positive to drugs, back-up was called and two more officers arrived.
All four were mowed down by the refrigerated truck but the Porsche driver, who is known to police, ran from the scene uninjured.
"It is an unprecedented event for us to lose so many officers in one event. Officers just doing their work, just doing their job," Victoria Police Chief Commissioner Graham Ashton said Thursday.
The 41-year-old Porsche driver apparently took photos at the crash site and shared them on social media, Mr Ashton told reporters.
The man, who has an extensive criminal history, has since made contact with police and will hand himself in.
The truck driver had a medical episode after the crash, blacked out and is in hospital under police guard.
Police raided the truck driver's Cranbourne home last night and are yet to reveal what they found.
Trevor, a cousin of one of the deceased officers and who drives a truck similar to the one involved in the tragedy, told Melbourne radio 3AW was shocked by the tragedy.
"It hasn't hit home yet, but the job they do, I don't think is respected enough," he said.
Premier Daniel Andrews asked all Victorians to pause and honour Victoria Police officers for the work they do.
"To live a life in the service of others is a deeply impressive thing, to lose your life in the service and protection of others is a tragedy," he told reporters.
Police Association Victoria secretary Wayne Gatt said the deaths sent shock waves through the policing community.
"The police force is waking up feeling numb, the members, the men and women of Victoria Police challenged deeply by this," he told Nine's Today show.
"It is every police officer's worst nightmare, going to the scene of something where an officer has lost their lives and here we have four. I don't know how you even start dealing with that."
Pulling over a car is routine work for officers.
