It’s 2.10pm Monday December 9. Two tour groups totalling 47 people - visitors and guides - from the US, the UK, Malaysia, China and New Zealand are walking near the crater on Whakaari/White Island.

At 2.11pm the island erupts.

The sudden and unexpected explosion sends ash, steam and rocks flying thousands of metres into the air and blankets the island in ash.

“It was something quite beautiful for that moment. The grey and the white erupting before our very eyes then a sinister grey rolling ash cloud over the cliff started to engulf the whole island,” eye witness Geoff Hopkins would later recount.

The immediate aftermath of the eruption is captured by American tourist Michael Schade, who was waiting with his group on their White Island Tours' boat to set sail from the island.

Only 30 minutes before Schade had been standing near the edge of the crater unaware that it was about to come to life in a deadly way.

The tourists, some of them from the cruise ship Ovation of the Seas which was docked in Tauranga, were captured on the island's camera walking near the crater just minutes before the eruption. Like tens of thousands of tourists over the past few decades, they were taking in the spectacular sights of New Zealand's most active volcano and getting as close as they could to nature's power.

2.17pm – Police are alerted to an eruption on Whakaari/White Island.

The initial reports they received indicate that about 100 people could be on or around the island.

Emergency teams immediately spring into action and are sent to Whakatāne.

2.24pm - On the island, Mr Schade’s group takes swift action. Crews from the boat risk their lives to rescue those they can, placing them on board their boat before heading straight for Whakatāne.

“[The] Boat ride home tending to people ... our boat rescued was indescribable,” he later wrote on Twitter.

Schade's mother attends to one woman in a critical condition as they make the 48 kilometre journey back to shore.

It’s 2.40pm and emergency rescue teams are en route to Whakatāne - and towards the erupting volcano.

What awaits rescue teams is an island drowning in ash. A scene intensive care paramedic for Auckland Westpac Rescue Helicopter Russell "Rusty" Clark would later describe as like something out of Chernobyl.

"Everything was just blanketed in ash. It was quite an overwhelming feeling,” he says.

As the Auckland Rescue Helicopter Trust descends to land, fresh ash swirls around the helicopter and the chopper is overwhelmed with the smell of sulphur.

The helicopter has to ascend, leaving rescue workers to begin their search for those left behind and injured on the island. At any moment the island could erupt again, and the crews are racing against time to locate and recover the victims.

At 2.45pm the media is aware of the erupting volcano, but information about victims on the island is yet to be established.

They aren’t aware that a boat full of causalities covered in ash with severe burns is on its way towards shore. There, St John Ambulance staff waits for them to arrive to transport those on the vessel to Whakatāne Hospital.

Three of the most critical patients are rushed onto the ambulances and taken to hospital where they are sedated and flown to burns units at Middlemore and Waikato hospitals.

As the victims begin to arrive on shore, hospitals across the North Island are notified mass casualties with burns are on their way.

Waikato, Middlemore, Tauranga and Wellington work through the night as the 31 patients arrive.

Among those seriously injured are newly-married couple Lauren Urey and husband Matthew from the US on their honeymoon, two British women and 24 Australians.

Evening falls as doctors and nurses work frantically on patients across the North Island, the death toll is announced – five people taken off the island have died.

More images also begin to emerge of plumes of ash spewing into the air and enveloping the island at speed.

With the island too unsafe for emergency services to be on, the New Zealand Defence Force sends out its P-3K2 Orion aircraft to carry out a surveillance flight over the island.

As night begins to fall several air searches by the police Eagle helicopter, rescue helicopter and NZDF aircraft found no signs of life. All eight people still on the island remain missing presumed dead.

At 9.45pm the Prime Minister arrives in Whakatāne.

As Tuesday dawns, the face of one of the victims is shown to the world for the first time, as his brother speaks out on social media.

"My bro Hayden Marshall-Inman has passed away doing the one thing he loved," brother Mark Inman wrote on Facebook.

An NZDF ship makes its way to the island at first light to deploy drones and other observational equipment over the island. Stilll shooting mud and steam into the air, a level three volcanic alert means the island still remains too dangerous to step foot on.

As the morning progresses the PM visits those who risked their lives and treated the victims.

As Tuesday afternoon begins the police release a statement calling the process of recovering the bodies a “heart-breaking situation”.

"Recovering the remaining victims and returning them to their loved ones is an absolute priority for NZ Police," it reads.

"Police are working closely with experts from GNS Science to get an understanding of the current environment on Whakaari/White Island and the likelihood of any further volcanic activity, as well as any risks posed to recovery teams by gases in the atmosphere.

Police also say an investigation on behalf of the coroner will be carried out in parallel with a WorkSafe New Zealand investigation.

In Wellington, Prime Minister Jacinda Ardern addresses Parliament, speaking of the St John first responders who boarded a coastguard vessel making their way to sea to become one of the rescue vessels to give first aid support.

“There were two of them, amongst many, many injured at that time until they reached other first responders on shore.

"I heard the story of those helicopter operators who when landing on White Island were greeted with devastation but did all they could to take off every survivor from that island and bring them immediately back to the mainland.

"I have no doubt they saved lives at great risk to their own personal safety.

“There is no limit to New Zealand’s capacity to mobilise, to respond, to care and embrace those impacted by tragedy. We are a nation full of ordinary people who do extraordinary things."

Tuesday night it's announced another person has died in hospital. 

At 7am on Wednesday the Ovation of the Seas cruise ship which carried some of the victims to Tauranga sails away from the Bay of Plenty.

On Monday night, the captain made an announcement over the speakers that many people didn't return to the boat after the eruption.

It postponed its departure to help with authorities.

A team from the cruise ship company remain on the site and at the hospitals to ensure people are supported.

7.20am – The HMNZS Wellington remains offshore of White Island, while police's Deodar III vessel leaves Tauranga for the island.

A five-nautical mile exclusion zone remains in place around the island for all boaties. 

10.30am - "We're working up the plan on how we'd actually go about and do that," Acting Assistant Commissioner Bruce Bird tells media in Whakatāne, after he was asked about the recovery of bodies.

"We've got to be certain of the environmental situation on the island...We can make some decisions once we've got all of that information.

"Safety is a huge priority for us and we've got to get this right."

GeoNet records a significantly increased volcanic tremor at Whakaari/White Island - indicating that volcanic gas pressures remain high. The Volcanic Alert Level remains at level 3.

48 hours after the lives of 47 people and their families were changed forever, hospitals around the North Island still continue to treat 30 patients, 25 are still in critical condition.