The Lemkin Centre, named after the Polish scientist who coined the term genocide, hopes the gathered testimonies will be used in future war crimes court cases.
When Lia and Alex woke up in Mariupol to the loud booms of explosions and shrieks of car alarms on 24 February, the young Ukrainian couple did not expect they would soon have to bury their loved ones in their own garden and fend off cold and starvation as Russian troops pounded the southern port city into dust.
Yet, they managed to survive and leave a city that now lies in ruins, narrowly escaping death in Russian bombardments, and avoiding being captured by Moscow's soldiers as they hunted for any Mariupol defenders.
The pair are now sitting at the newly-formed Lemkin Centre for Investigating Russian War Crimes' office in Berlin, telling their story in vivid detail as part of a programme collecting witness testimonies about war crimes to help tribunals, journalists, and future historians build a case against those responsible.
The Lemkin Centre's fieldworkers have been visiting shelters across Poland and in Berlin, interviewing survivors and recording exactly what happened to them.
They're passing out forms and inviting eyewitnesses to recount their traumas -- the kind of gruelling and emotionally-challenging work in documenting war crimes that often goes unnoticed.
The centre, founded by Poland's Pilecki Institute in the early days of the Russian invasion of Ukraine and named after the Polish lawyer who coined the term genocide, has so far gathered researchers specialising in totalitarian crimes and experts in international humanitarian law of armed conflicts.
It also relies on a network of Ukrainian- and Russian-speaking volunteers, who, after going through training by the centre's experts, have made it their mission to listen to and record anyone willing to talk about what they witnessed and endured over the past months.
The testimonies paint a grisly picture of the Russian government's intent to use all available means -- atrocities included -- to take absolute control over their western neighbour, the centre's head told Euronews.
"It was clear from the very beginning of the first day of the war and from Putin’s speech that war crimes are consciously inscribed into [his] methods and tactics," Lemkin Centre Director Dr Magdalena Gawin said. "It is a kind of barbarism."
Facing a tank to bury their grandmother
At the centre's office near the Brandenburg Gate, Alex and Lia recalled everything they could from the very first day of the invasion to their escape from Mariupol in a beat-up car the two drove all the way to the German capital.
After waking up to missile strikes on a harsh wintry morning in February, the two first managed to find their way across the industrial city on the Azov Sea shores to Lia's parents' house despite heavy bombardment.
Lia’s grandmother had Alzheimer's, and the family had just recovered from COVID-19, so they decided to stay put for a while. At first, the shops were open and Alex even managed to buy a birthday cake, but everything changed when the electricity and gas stopped.
Shortly after that, the supermarkets were bombed. Alex recalled a 5-metre-deep crater where a store used to be. Alex thinks it was targeted.
While Lia's grandmother struggled with her health, unable to look after herself, the family -- who took round-the-clock care of her -- prepared themselves for her eventual death and found some consolation in the fact that she would not die alone.
But a big explosion at 5am one morning had them all dashing to the basement. When they emerged about half an hour later, their grandmother had died. Lia’s mother was howling with grief and disbelief, the two remember.
Organised funerals were already impossible and, fearing shelling and gunfire, residents began to bury their loved ones in parks and backyards, without much ceremony to speak of.
A trip to acquire a coffin revealed that Russian forces had arrived: suddenly, there was a tank waiting outside their building. The turret started turning, and then the tank started shooting at them.
“This was the first time Lia wasn’t complaining about my fast driving,” Alex jokes, his dry humour a shield against the horrors they lived through.
It took them three days to dig Lea’s grandmother’s grave at the bottom of the garden next to an apple tree because the ground was frozen solid. “It was the coldest day of my life,” Lia said, pondering how her mother still talked every day about returning to Mariupol and burying her properly.
'I was praying we would die quickly'
Surviving took an extraordinary amount of energy and time, they explained. Going to collect water became an ordeal that involved waiting three hours in a queue and carrying heavy bottles a hundred metres up steps from an underground water source.
So did gathering firewood to burn in a barrel in the living room to heat against the harsh cold of the first weeks of the invasion.
In the occupied city, reliable information was as scarce as food and water. There were constant rumours about humanitarian aid arriving, but a few weeks in, many had run out of food when the Russians started bombing nearby.
While at least half the population fled for safety, the other half remained unprotected and vulnerable. “They didn’t care if they died from hunger, or from a bomb,” said Lia.
Luckily, Lia’s parents still had potatoes and preserved vegetables left over from winter, but they had no idea how long they would be stuck there so they had to ration it strictly. Others were not as fortunate, she recalled.
The bombs kept getting closer to the shelter, the walls shaking from impact. “We weren’t brave,” Lia mentions. “At the start, I prayed not to die. By the end, I was just praying that we would die quickly.”
The day they left Mariupol was the first day since the beginning of the war when the signal on their radio was clear.
Hearing about the humanitarian corridor that would allow them out of their city, which had become a prison on fire, the family suffered another blow -- the telltale whizz of a Russian projectile and a boom as their car was destroyed.
When they sped out of the city in a replacement car, the sky was red from the fire of all the burning buildings. As they were leaving, they saw the tank that shot at them had been destroyed. They laughed.
They saw Russian soldiers face-to-face for the first time at the checkpoints. The troops made Alex take his t-shirt off, inspecting the black tattoos that cover his arms for Ukrainian army symbols. One of the soldiers asked them if they could buy any drugs or weapons from them.
“It was so ugly,” Lia sighs. They drove the beaten-up car all the way to Berlin, which they had visited in January and talked about moving to, but they could have never imagined the circumstances that brought them here.
Mariupol officially fell on 16 May, after the last pocket of Ukrainian resistance blockaded in the Azovstal steel mill surrendered to the Russian troops.
The city that once had about 430,000 residents is considered to be almost completely destroyed, with some 90% of it thought to be uninhabitable.
Mariupol's last ambulance driver safe in Warsaw
Another of the Lemkin Centre’s main witnesses, Kateryna, only managed to escape after Moscow's troops had already taken control of the city. In the centre's Warsaw office, she told Euronews about her harrowing experience as the last ambulance driver left in Mariupol.
She drove a grey St John ambulance van around the bombarded streets during the siege, helping almost 100 people get to hospitals and shelters. Kateryna recalled how bodies started to appear in the streets and were left there, with no one to carry them away to be buried.
“People had been killed by shrapnel or bullets, but many of them, especially the elderly, had died of starvation or hypothermia. No one was removing the corpses from the streets," she said.
"While I was attending the wounded, people ran up to me and asked when I would start taking the bodies away. It was a very difficult psychological experience.”
Kateryna burst into tears when describing how she saw some 2,000 dead bodies with her own eyes. The shooting made it impossible to go in and help, despite the desperate pleas of bystanders.
“Russian units were occupying our flats, and I saw them shooting at civilians from the streets from the apartments. I was travelling around with a medical kit, trying to evacuate them to the main hospital, but then the Russian soldiers captured it too, using the patients and medical staff as human shields.”
On her last day in Mariupol, the road was destroyed, so she had to travel on foot. She saw a car that had hit a tree, with the driver already dead inside.
But then she spotted a teenage girl sitting in the back of the car. “Get out, we need to leave, they’re bombing here,” Kateryna told the teenage girl. On the other side of the car, a woman was lying in a pool of blood, moaning.
She realised that these were the girl’s parents, but she knew that with projectiles flying overhead she could only help one person -- so she had to make the horrifying choice between saving the mother or the daughter.
Seeing that the younger woman was still able to walk, she chose the daughter. When she got her down the stairs of the shelter, Kateryna saw that the woman's shirt was so full of blood that she was not able to wring it out.
When she was finally evacuated from the Black Sea port city, thousands of dead bodies were still on the streets, but she received messages from friends saying that Russian soldiers forced the remaining civilians to clean up the bodies to hide their crimes.
Now safe in Warsaw, Kataryna believes she will never forget what she has seen.
'Witnesses of the Age'
Established by the Polish parliament in 2017, the Polecki Institute has mostly focused its work on researching crimes committed by both Nazi Germany but also the Soviet Union.
It has been collecting first-hand experiences of Poles through its "Witnesses of the Age" project, with a number of video testimonies available on YouTube having ordinary people recall their experiences from surviving a Nazi concentration camp for children to the Red Army's campaign of mass rape after it entered Warsaw in 1944.
The testimonies by Ukrainian survivors will now become a part of the same collection, keeping the memories of the likes of Lia, Alex and Kataryna alive well after the war.
To Dr Gawin, the similarities between the crimes committed then and what Russian troops are accused of doing in Ukraine today speaks of a continuation, but also a lack of reckoning with its own atrocities, as the Soviet Union never conducted its own war trials.
The atrocities committed since February "reminds in many ways of the German and Soviet occupation [of Poland] from 1939," Dr Gawin said.
"The extermination of local elites and intelligensia in Ukraine? That is a perfect example – Russia killed 20,000 Polish representatives, officers and intellectuals at Katyn. The perpetrators were never punished for that.”