This is the phone call that will be made when you die.

"We do a CT scan and take a very small amount of blood," the operator says, before pausing to listen to what's being said on the other end of the line.

"We have to do that just to find out a cause of death. For someone so young, the cause of death is not so obvious."

The four people sitting in a semi-circle at their desks are like a call centre for the dead.

They work in Melbourne's Coronial Services Centre.

You'll find it if you walk into the Coroners Court (a specialist court that investigates certain types of deaths), go down a hallway into the Victorian Institute for Forensic Medicine.

The institute's doctors help investigate deaths reported to the coroner, examine alleged offenders and support victims of crime.

The four people we meet in the Coronial Service Centre are among the first to know when someone dies in Victoria.

About 6500 times each year someone, usually a police officer, phones to report the discovery of a body.

Other calls, like the ones taking place now, are discussions with families about what happens next.

These four people are extraordinary in the way they navigate grief, moving from gentle, matter-of-fact explanation to heavy sympathy in a matter of minutes.

"You have a lot going on ... You'll be glad to see the back of 2017," one says, listening as the caller unloads the burdens of the year.

"Have you got any support with you? ... It probably hasn't hit you yet ... You don't realise how much it does until later ??? Let them know Stephanie is with us at the Coroner's Court."

They always use the name of the deceased and almost always in present tense, as if they are still alive because to families, it still feels like that.

The toughest conversations are often about autopsies.

In the old days, nearly everyone had an autopsy; now, most don't, because the cause of death can often be established without it.

But when it's not clear, the senior next of kin is asked for their permission. If the OK isn't given, a coroner must weigh in.

One of the call-takers, Sarah Long, is an intensive care unit nurse.

She is getting ready for a family to come in to identify the body of their father.

Sometimes families stand behind the glass window, she said; other times they will go in and hug and kiss their loved one.

Sarah Long, Victorian Institute of Forensic Medicine.

She'll never forget the series of phone calls she had with a distraught father who didn't want his son to undergo an autopsy, but because he died during a procedure, needed one.

"I was getting off the phone and crying as well," she says. "We tried so hard."

THE SMELL

We are now in the mortuary. There's no polite way to say this: the smell of a decomposing body hits you. It's a smell you don't forget.

It's not usually this bad, but it depends on the state of the bodies that come in that day. Not that it bothers Dr Linda Iles any more.

"People can get used to a smell in five minutes," Dr Iles says.

"So no, I don't notice it."

Dr Iles is the head of forensic pathology and we're standing in what's called the homicide room.

It's all rather clean - the walls and floors are soft greens and creams and blues with sparkly scalpels on benches and ... wait ... long-handled garden shears?

Photo: Eddie Jim

There's a table in the middle of the room where autopsies in some of the country's most high-profile murders have been performed; pathologists can tell from their injuries that the victims went through hell.

"Sometimes it gets to the point where you just don't know what happened before and after death," another forensic pathologist, Dr David Ranson, says.

Homicides are often the longest autopsies to carry out (Dr Iles has been in here for 12 hours before), not because of the complexity but because the pathologists must document everything.

If someone had, for example, 80 stab wounds, then the size, shape and location of each one needs to be described.

There is a viewing area where homicide detectives can sit and watch an autopsy take place.

A TV screen broadcasts close-ups of the procedure. The detectives can ask for the camera to zoom in on something that interests them.

Sometimes key information will be provided to police so it can be used when interviewing a suspect.

A toxicology lab is available to test if substances were in someone's system when they died, whether illicit, prescription or otherwise.

Sometimes they'll find poisons like strychnine or cyanide.

"They challenge us because they're not part of our routine analysis," says chief toxicologist Dimitri Gerostamoulos.

An extracted blood sample injected into a vial for testing. Photo: Eddie Jim

The reason pathologists have to be so fastidious is they often wind up in the witness box in murder trials.

Science is often not straightforward - think of the Gerard Baden-Clay case where forensic experts weighed up whether the marks on his face were scratch marks from his dead wife or from a razor.

Dr Ranson is standing by a table that has some multi-coloured wands that look like pick-up sticks. Ok, we want to know what those are for.

"We use them to measure bullet trajectories," he says.

Photo: Eddie Jim

IDENTIFYING THE DEAD

The vast majority of cases reported to the coroner are not suspicious.

It could be an elderly person who has fallen, a driver of a car that hit a tree, someone who overdosed on medication, a young person who took their own life.

Most of the time their identity is obvious; a family or friend may have found them or they might be in their own house when it happens.

Photo: Eddie Jim

But sometimes the question of who a person is can't be answered so easily.

One of the most useful clues is found inside our mouths.

"Why are teeth so good? Well they're strong, they survive," says forensic odontologist Dr Richard Bassed.

Teeth are particularly helpful in cases where someone is heavily decomposed or has been badly burnt. In mass fatality incidents, they can be used to distinguish one body from another.

"In the case of the Black Saturday bushfires, often all that was left were teeth," Dr Bassed says.

"They can survive 1000 degrees for an hour and a half."

People also tend to get lots of dental treatment - such as fillings, crowns or braces - that is unique to them.

Each tooth is a piece in the puzzle that can unlock the answer.

Identifying someone by their teeth does require a bit of leg work.

There is no central repository for dental or medical records, which often means tracking down someone's dentists by asking their family.

The idea is to gather as much information as possible to get a complete picture of how a person's mouth looked when they died.

And often pictures tell the best story.

While someone's exterior appearance may have changed dramatically after death, an x-ray of their mouth antemortem (before death) and postmortem (after death) will look identical.

If dental records can't be found, a CT scan can be taken and even compared with a person's Facebook photos.

"We can identify people without having to go into the mortuary and look at or examine or dissecting the body at all," Dr Bassed says.

WHEN THERE IS NOTHING LEFT

Keen viewers of TV shows like CSI are probably asking by now, "Where's the DNA?"

While there has been an explosion in the field of DNA, it only tends to be used to identify someone when other methods have failed.

Just before we enter the forensics lab, we have to swab the inside of our mouths. This is so that if we leave DNA behind, they can account for it - especially if you have a biological tendency to leave your DNA everywhere.

"There are high shedders," says Dr Dadna Hartman as she tags and bags our samples.

"Some people just are."

The technology is crucial when remains, lying dormant for decades, are found and police don't know who they are.

Swabs from a bladder, blood or even someone's toenails can produce quality DNA, but bone is also regularly used.

A few years ago there was a case in which remains were found in the bush by workers digging trenches for a bushfire.

The DNA matched a sample given to police from the family of a man who went missing bushwalking 20 years earlier.

There was another case where DNA provided long-awaited answers.

The family of a Melbourne teenager who went missing after leaving home in 1971 found out she had run away and assumed a new identity.

Her brother had publicly called for information in 2010, which was seen by the daughter of his long-lost sister.

The daughter had been trying to find out more about her mother after she had died in a car crash in 1976.

The daughter, who was just eight months old when her mother was killed, provided a DNA sample for Dr Hartman's team. That unravelled the case and bought two families together.

Most people who are brought into the mortuary are identified within 24 hours.

It's rare but those who can't be identified are kept for up to a year before they are buried in an unmarked grave.

Dr Dadna Hartman and Dr Dimitri Gerostamoulos in the DNA lab. Photo: Eddie Jim

INVESTIGATING WHAT HAPPENED

Once someone is identified, it's up to the coroner to establish what happened to them.

Not all deaths go through this stage, only those that are considered "reportable". These include deaths that are violent, unexpected or happen during medical procedures.

Sometimes in an investigation, the coroner will identify a broader problem and will make recommendations to effect change to prevent further deaths.

Such was the case when the coroner called for the trial of a safe injecting room in Richmond after a spate of heroin overdoses in inner Melbourne, which the state government approved in October.

There's no rhyme or reason as to how many reportable deaths come in each day. Today was tracking at seven so far, yesterday was 18, and Monday - always a busy day because of the lag from the weekend - was 40.

"Forty on a Monday is not bad," Coroner Philip Byrne says.

Mr Byrne is the coroner-on-duty today and he's sitting in an office next to the head of coronial admissions and enquiries, Dr Jodie Leditschke.

Phillip Byrne, Victorian Institute of Forensic Medicine. Photo: Eddie Jim

Mr Byrne been here for 35 years and mostly enjoys the challenge of the work.

But some cases take their toll and he feels the weight of the decisions he makes about the cause of death and reasons behind it.

"There are days when I wake up at 5 o'clock in the morning and think of what I'm going to do," he says.

"We (the coroners) are all human."

Suicides make up a significant proportion of Mr Byrne's work, he says, so much so that he has a saying about the decisions he makes about them: "Findings of great moment," he calls them.

"They are findings of which can reverberate upon a family for generations and impact on the memory of the deceased."

There are 10 coroners like Mr Byrne and they handle between 650 to 700 cases a year. It's a massive workload. The aim is to clear each case in three months but some may take six or even 12 months.

Not every case leads to an inquest, however every death is investigated. State Coroner Judge Sara Hinchey says there is a bit of a misconception about the difference between the two. An inquest will be launched when cross-examination is needed.

"Sometimes people think that if a case has not gone to an inquest then it's not being thoroughly investigated, but that's not true," she says.

"If we can finalise that investigation without putting a family though a public hearing, we will do so."

Associate Professor David Ranson, Associate Professor Richard Bassed, Dr Jodie Leditschke and Dr Linda Iles in the mortuary. Photo: Eddie Jim