A woman's body lay in her isolated home for weeks through the summer heat before neighbours noticed the smell - and then the flies.
A man's blood was splattered room after room throughout the house from a dreadful fight.
Police and other responders came and went, before another specialised group took over.
Clad in white biohazard suits and breathing through respirators, double-rubber gloved and booted, the Crime Scene Cleaners team began its demanding task of cleansing the awful scenes.
On any given day, the forensic cleaning technicians – or trauma cleaners – can remove blood and body fluids from places of horrific crime, suicide and lonely death, as well as scour mould and filth from pest-infested hoarder-houses and rental properties-turned-P labs.
"It's a challenging job and requires "a strong stomach and someone that is exceptionally thorough", says Carl Loader, who together with partner Tara-Jayne Stapleton started Crime Scene Cleaners a decade ago.
It is also rewarding returning order to the sites for those traumatised and overwhelmed by what has happened in them.
"I feel honoured that we're able to offer this service to help people," Loader says.
"I've had emails saying thank you for your help and your compassion at this hard time.
"That's very rewarding."
The Christchurch couple launched the company after experiencing first-hand the impact of a trauma scene and confusion around the process of having it remediated.
Shocked by the ghastly sudden death of a man at one of their rental properties, Loader says they struggled to find anyone willing to clean the gruesome scene.
And business is booming because of mental health issues and hoarding.
Crime Scene Cleaners, with bases in Auckland, Wellington and Christchurch, now has about 30 staff, operating across 24 hours a day, 365 days a year.
Late night requests often involve cleaning up scenes of suicides and violent incidents including homicides, Loader says.
"It's very traumatic. (People) want something done immediately."
One crew arrived back at base in the evening from decontaminating a meth house, to a request for the ghastly scene of a sudden death to be cleansed as quickly as possible before relatives were confronted with it.
"Staff got home at five in the morning."
Another call came shortly before midnight after a man had accidentally severed an artery.
"There was just so much blood around, [the family] just wanted it cleaned up before they got him home from hospital."
Safety is paramount for trauma cleaners, who cleanse blood, other body fluids and waste, mould and P residue, and rid places of vermin.
"We did one where the lady that passed away had MRSA - it's a notifiable bacterial infection," Says Loader.
"With blood, you don't know whether the person's got HIV or hepatitis, so we have to take great care."
Another callout came after workers found discarded syringes in planter boxes at a public building.
"We had to hand sift 66 planter boxes looking for needles."
Crime Scene Cleaners was also called in when staff at a luxury hotel checked a room in which a professional couple had stayed the previous night, to find "faeces smeared on the walls".
"They [had] checked out the next day like nothing was wrong."
At a number of hoarding sites his company has cleaned, the toilet has been blocked for considerable time, Loader says.
Cleaners have even had to dispose of stored bottles of urine and bags of faeces.
Bodies are sometimes undiscovered for weeks or even months - especially isolated elderly - and have decomposed, fluids seeping into furnishings and floorboards.
Unattended death scenes and hoarding sites can attract rodents and insect pests.
And gunshot wounds and severed arteries can splatter blood across walls, ceilings and floors.
Loader has seen floors matted with maggots.
"You walk in [with] your boots and gear on [and] it's crunch, crunch, crunch."
The trauma cleaners are given in-house and external training courses in negotiating potentially-perilous sites and using the customised chemicals required to clean them.
An assessment is done and they are kitted up in protective clothing before entering buildings.
Respirators and face visors are worn to shield from bacteria, blood-borne disease, and chemical fumes.
Biowaste from trauma sites is double bagged and taken to medical waste disposal facilities.
Cleaners' rubber gloves and booties and biohazard suits are bagged and disposed of, sometimes incinerated depending on the situation.
Ozone machines and air scrubbers are some of the specialised equipment utilised to remove foul odours.
The odour of decomposing flesh is pungent, Loader says. "It's a smell you don't forget."
"[When] we can't economically get rid of the smells, we sometimes have to cut the floor out of the place."
Cleaning the trauma sites is also physically demanding.
"[We] scrub, spray, clean, and it's all labour-intensive," says Loader.
"We have powerful lights that we put on, 'cause you just go back over and over and over and make sure you're getting everything."
It takes hours, sometimes days, to cleanse the scenes.
Loader has drunk as much as three litres of water cleaning inside a sealed home in a full biohazard suit on a hot summer day.
He also offers professional counselling to staff, who have to deal so closely with the aftermath of tragedy and violence, he says.
They gather and talk through their work, including impacts it may have had on them, at the end of jobs.
"Before we go (on a job) we have a discussion about what process we're doing, and when we've finished a job we always have a debrief."
Sites of suicides can be especially confronting.
His teams have cleaned scenes where people aged in their mid-teens to mid-60s have taken their own lives, Loader says.
"You go home and you do think about it."
The 54-year-old works out to unwind.
"I exercise every day, and I box three times a week.
"It's a health thing but also it just clears your mind."
Stapleton, 45, runs Crime Scene Cleaners administration, researches chemicals and safety equipment, and prepares remediation plans.
But she has, and continues to when needed, cleaned at trauma scenes including sites of fatalities.
She still vividly remembers a holiday season call-out where a woman had died in her home in an accident.
"In her lounge room she had strings from one corner to the other, and on the strings were all the Christmas cards," Stapleton says.
"She had a lot of them, so obviously lots of people appreciated her.
"And she had her Christmas tree up."
"That was quite sad."
Crime Scene Cleaners clients include victims' families, insurance companies, real estate agencies, taxi companies, police and funeral directors.
Cleansing of the sites is also about restoring dignity, Loader says.
Where someone has died, Crime Scene Cleaners refers to the deceased by their name to make the clean-up a "wee bit more personal".
"We try to actually give the person identity."
Keepsakes and sentimental items, including photo albums, are cleaned and returned to family.
In one case, relatives asked if it was possible to keep an eye out for their loved one's prized military medals.
"And by luck one of my guys was emptying a drawer with socks in it, and there was [the] medals in [a] sock."
Loader recommends, where appropriate, sites where someone has died are blessed after cleaning is done.
"It gives people some closure and some comfort."
Hoarding is a big problem.
"You'd be surprised how much is out [there] in New Zealand," Loader says.
Some homes are so full, occupants have made little alleyways through collections of objects to be able to get in and out of the building.
"It's actually a danger for them to be in the house because there's so much stuff in there, and it's just piled and piled and piled. If it fell over, you'd be trapped."
One man's two-bedroom flat was so full, cleaners had to clear the doorway for one of them to access a passageway "like a hole" to negotiate their way through the home.
It took a five-strong team two-and-a-half days to clean the flat, filling seven skip bins.
Hoarded objects include cans, bottles, newspapers, books and stuffed toys – each item precious to its owner.
Loader tries to have owners off-site when his team is cleaning.
"But occasionally they want to stay on site and it becomes just like you see on TV where they're physically trying to hang on to each piece.
"You're throwing something out and [they're] trying to retrieve it."
The company is experiencing an increasing number of jobs "that are resultant of some type of mental health issue", Stapleton says.
"It's something that we do encounter on a regular basis."
"The mental health system in New Zealand is very flawed, and there's lots of gaps in it."
Business has grown exponentially since the company started in 2010.
"We just started with one job, and [initially] we got one job every few weeks or a month.
"Now, there wouldn't be a day go past we don't have a job."
Loader is aware of at least half a dozen other cleaning firms around the country offering trauma and forensic cleaning among their services.
"We don't do commercial type cleaning. Where [routine] cleaning stops, we start.
"We're extreme cleaners."
As the need grows for trauma cleaning, Loader says he is attempting to demystify and raise awareness of the critically necessary industry.
While his company has unmarked vehicles for jobs where discretion is required, they also have sign-written vans informing of their services.
Reactions have been varied – one woman passerby telling him the imagery was too confronting, another telling him, "you did a job for a friend of mine, and you guys do a great job".
"There's all sorts of things as New Zealanders we're scared to ask about," Loader says.
"We're informing people that these things are part of every day life and what [can be done] when they happen."
Crime Scene Cleaners staff include a nurse, former soldier and a qualified engineer.
Backgrounds usually include some cleaning experience.
They must be very detail-orientated people, Loader says.
He won't specify what his staff earn, but it is "considerably more" than standard rates for cleaners – "as you would expect".
Common traits among his trauma cleaners are liking "doing something that's different and a little challenging and being able to help [others]".
"We're resolving problems that other people can't."
His staff work with speed, respect and compassion, provide support to often overwhelmed families and do an "extremely high quality job", Loader says.
Their aim is to restore a trauma scene to a state where there is as little sign of distress or damage as possible.
"We get in, we do our job, we hand it back to the people who are in charge and we leave."