Emmanuel Durand had only arrived in Kharkiv on the overnight train a few hours earlier when he heard the first explosion.
A thunderous clap brought into focus just how close the 52-year-old structural engineer from France was to the frontline of the war in Ukraine.
The Ukrainian members of his team, who by this stage had endured three months of the Russian invasion, were quick to reassure their nervous companion.
"The shelling is over there [in another neighbourhood]. Here it's okay," he recalled his fellow volunteers saying, as if they were talking about the weather.
Durand, an expert in the 3D laser scanning of structures, had arrived in Ukraine's second-largest city on a 17-day mission to document the destruction of culturally significant sites across the nation.
In its ruthless campaign to capture territory, the Russian military has pummelled huge swathes of the country into the ground.
In addition to the loss of homes, lives and livelihoods, scores of Ukraine's historic buildings, monuments and cultural centres — some of which date back centuries — have also been damaged or destroyed.
Durand hoped that by producing intricate 3D models, he could offer the world a unique perspective of what was happening to some of these Ukrainian sites.
His first job was Kharkiv's historic red brick fire station and watchtower.
Built in 1887, the building is a relic of the city’s industrial revolution.
The model reveals the carnage of recent shelling.
The roof has been left in tatters.
Windows have been blown in.
Rubble surrounds the exterior
And century-old brickwork is smashed into pieces.
Using a fist-sized device that bounces lasers off surfaces, Durand spent two days meticulously capturing every feature of the building, inside and out.
The process involves moving from location to location around the site capturing millions of points of data to create a near-exact digital replica of the building.
It's a delicate task that requires you to find the right balance. Overdo the scanning and you collect so many data points that it will overwhelm the task of processing the information. Too few data points and you risk ending up with an incomplete picture.
The final fire brigade point cloud – the technical name for the 3D model – is made up of more than 1.6 billion points. The model you saw above was just 3 million points.
"The advantage of the laser scan is that we get every single brick,'' Durand said.
The fire brigade is one of more than 170 cultural sites that UNESCO has verified as damaged or destroyed since the invasion began in February. A quarter of those buildings are in the Kharkiv region.
The list includes churches, museums, historic buildings and monuments, like the Drobytskyi Yar Holocaust Memorial, a menorah-shaped monument overlooking a ravine in Kharkiv where an estimated 15,000 Jews were murdered by Nazis in World War II.
Ukraine's Ministry of Culture is keeping its own tally. To date, it has listed more than 400 sites of cultural importance that have been damaged in the war.
When the invasion began, huge efforts were made to protect artefacts. Artworks were packed up and shipped out of harm's way; immovable monuments were wrapped and reinforced.
But there was little that could be done to protect Ukraine's historic buildings from Russian shells.
That's why people like architect Sergey Revenko turned to technology to help preserve what they could of his country's cultural identity.
Revenko was living in Kyiv when the shells began raining down on his city.
When Russian forces withdrew from the outskirts of the Ukrainian capital, he decided to head beyond the city limits to document the trail of destruction left behind by the Russian army.
Revenko is an expert in photogrammetry, a process which combines multiple images to create complex three-dimensional models.
He wanted to use his skills to capture the raw aftermath of war. He wanted people to see for themselves what had happened to his country before the clean-up began.
Revenko packed his camera and his drone and left his apartment in Kyiv. He headed north to the city of Irpin, which at one point during the invasion was declared the most dangerous place in the wider Kyiv region.
The first stop was the Irpin bridge.
In the opening days of the invasion, the bridge was destroyed by Ukrainian soldiers to slow the advance of the Russians into Kyiv.
Revenko's scan captures the bridge, as it was just days after the Russians withdrew from the area.
It was a scene of chaos.
The bridge was split in two, revealing the enormous concrete supports beneath.
A white van flipped upside down and collapsed into a pile of rubble on the riverbed below.
“The goal was to present [the war] in a new way," Revenko said.
"And maybe to get our audience to … feel the craziness of the Russians, or how depressing it was."
The bridge became a symbol of Ukrainian resistance. Photos of people fleeing the fighting passing underneath the bridge also helped highlight to the world the devastating humanitarian toll of the war.
Because of its significance, there are plans to leave the destroyed bridge as a monument and instead construct a new bridge next to it.
After publishing some of his scans, Revenko was contacted by a Ukrainian government official, who invited him to join Emmanuel Durand and a team of cultural experts.
Together, they combined their expertise to create hyper-realistic models of the destruction of cultural sites.
In addition to their work in Kharkiv, they also visited Chernihiv where they scanned the regional youth library — once home to the Vasyl Tarnovsky Museum of Ukrainian Antiquities.
This 19th-century Gothic revival building withstood Bolshevik shelling in 1918-1919 and fighting during World War II, according to Ukraine's Ministry of Culture.
Within weeks of the Russian invasion, the historic building had been blown to pieces.
Revenko still remembers the look of shock on Durand's face when he saw the deep crater left behind by a Russian missile.
The impact tore one side of the building from its foundations.
3D expert Miguel Bandera created this model combining Durand's base scan with Revenko's images as the texture draped over the top.
The detail allows us to step through the building, offering a unique perspective on the devastation inside.
Rubble is littered across the floor.
Library books and shelves are left in tatters.
Revenko continues to publish more evidence of the destruction of his country. He is even attempting to build his own laser scanner. Seeing what is happening to his country drives him to continue his work.
"I feel like they are hoping to destroy as much history as they can," Revenko said. "You get angry about that. [But] this anger gives you the power to go further and to do more."
Under international law, the intentional destruction of cultural heritage is considered a war crime.
That can include "intentionally directing attacks against buildings dedicated to religion, education, art, science or charitable purposes, historical monuments or hospitals", according to the body responsible for pursuing allegations of war crimes in the International Criminal Court (ICC), the Office of the Prosecutor (OTP) for the ICC.
One organisation seeking to hold the Russian Federation accountable for crimes against culture is the Ukrainian NGO, the Regional Center for Human Rights (RCHR).
The organisation was set up in Crimea in 2013. After the Russian invasion of the peninsula in 2014, the centre moved its operations to Kyiv where it began collecting evidence of human rights abuses and war crimes in Crimea.
As a result of its investigations the RCHR has made 11 submissions to the International Criminal Court – one of which focused on the destruction of Ukrainian cultural heritage.
The brief of evidence included examples of cultural artefacts being removed from Crimea and sent to museums in Russia; the illegal excavation of archeological sites in the ancient city of Tauric Chersonese and the destruction of cultural sites during the construction of the Tavrida Highway linking the Crimean peninsula to Russia.
Lawyer Daryna Pidhorna spearheaded the RCHR's investigation into the alleged culture crimes in Crimea. Since the invasion on February 24, she has been collating more evidence that she believes highlights the deliberate destruction of cultural sites in other parts of Ukraine.
Pidhorna said while there were many cases of cultural destruction across mainland Ukraine, her work had focused on three of the most egregious examples: the damage and occupation of a historic 18th-century fortress known as the Round Yard in Trosianets in the Sumy region; the shelling of a drama theatre in the southern port city of Mariupol; and the looting and destruction of a museum, also in Mariupol, that housed masterpieces from 19th-century artist Arkhip Kuindzhi.
When finalised, the evidence will be supplied to Ukraine's national prosecutor, the International Criminal Court and the International Court of Justice.
"If we cannot stand for our country, for our language now, then we could not stand as people in the future, because we will [have] lost everything," Pidhorna said.
"We will lose our origins, we will lose our roots, we will lose our culture, our language, everything that could make us individuals."
At the international level, prosecutions of cultural war crimes are rare. The first conviction of the intentional destruction of cultural property as a war crime was only handed down in 2016.
Islamic militant Ahmad Al Faqi Al Mahdi was handed a nine-year sentence for directing attacks against religious and historic buildings in Timbuktu, Mali in 2012.
The Ukrainian task force set up to investigate Russian war crimes reportedly has a backlog of more than 25,000 cases.
But the challenges in prosecuting cultural crimes have not swayed the resolve of Pidhorna and her colleague Kateryna Petrova, the RCHR deputy head.
For Petrova, pursuing justice for what has happened to her country's heritage goes to the heart of what it means to be Ukrainian.
"It's all about ... accountability for trying to destroy the national identity," she said. "In my opinion, it is even worse than destroying buildings, and killing people, because you're destroying the history of the whole nation and their identity."
