On an intersection in the centre of Odesa, near an upmarket hotel and across from a high-end clothing store, a wall of sandbags, barbed wire and steel tank traps block the road to the city's famous opera house.
The streets around the city centre, once heaving with crowds of tourists from Russia, Turkey and America, are now deserted. Only soldiers patrol past shuttered shopfronts and street signs wrapped in plastic.
The words "liberté, egalité, fraternité" have been sprayed in Ukrainian blue and yellow paint on a slab of concrete laid across the cobblestones.
Odesa is known as the pearl of the Black Sea, and for Russian President Vladimir Putin, it would be a major strategic prize.
Capturing it would help him cut Ukraine off from its southern coastline, although landing troops on the city's beaches would be a major challenge for an invading force that has already been moving slower than expected.
In 1941, when Odesa was bracing for an attack by the Nazis, the city fortified itself from the inside out.
Now, more than eight decades later, it's doing it again.
Authorities and residents are on high alert, particularly for Russian warships on the horizon — Russian-controlled Crimea is only about 300 kilometres away by water.
For weeks now, its residents have watched intently — on popular apps like Telegram — the endless stream of updates on Russia's destruction of Kharkiv, Mariupol and Kyiv.
How long would it be, they wondered, before Odesa was added to that list?
Today, they may have received their answer: Authorities in Odesa say Russian forces have begun striking residential buildings.
Odesans say they are defenders of their city
Odesans from all walks of life have been busy preparing their city for the coming storm.
"It doesn't matter if you're a woman or you're a man," said Viktoria Melnyk, a 23-year-old tour guide from an underground tunnel beneath an Odesa neighbourhood.
"You are [a] defender."
Regular air raid sirens are a daily reminder to Odesans that the Russian military is easily within striking distance.
Early on Monday, a residential area on the outskirts of the city was hit by a Russian air strike, according to local officials. Nobody was injured.
Ms Melnyk has pushed rising feelings of terror and despair out of mind.
"If we cry, who will defend the country?" she said.
How Odesa went from international haven to fortress
All over Odesa, buildings and spaces once used for teaching or office work have been repurposed to support the war effort.
A school not far from the centre has become a warehouse for donated or handmade goods to be sent to soldiers fighting invaders in southern cities like nearby Mykolaiv and Russian-occupied Kherson.
In a makeshift pharmacy on the ground floor, a group of women has sorted household drugs into buckets labelled things like "bandages" and "anaesthesia".
Some deployed troops are running low on tourniquets – small nylon bands used to stem blood flow from wounds – and have been forced instead to use inner tubes from bicycle tyres.
"Our soldiers won't make it without us," Natalia Lavrova, a volunteer who before the war worked in the tourism industry, said.
Each classroom of the school had been given some new purpose. Shelves of schoolbooks and posters showing bright cartoon images have been obscured by piles of clothing and equipment.
In one classroom, a volunteer fashioned homemade periscopes from PVC pipes and mirrors. Near the blackboard at the front lay a heap of half-sewn flak jackets.
'It's our duty'
On a beach in Odesa, where children once used to play, hundreds of volunteers frantically scoop sand into white plastic bags.
Once they're sealed, they are passed down an enormous human chain that takes them onto the back of trucks.
The sandbags form the building blocks of the barricades that can slow or cushion the potential spray of bullets and shrapnel.
It's a sunny day but the wind from the Black Sea is icy cold and between stints on the production line, volunteers warm their hands near a campfire.
Before the war, these people were all busy with their normal jobs.
Alexander Perepelitsa, 39, is ordinarily a pianist in Odesa's National Philharmonic Orchestra, but he has joined the army of volunteers on the beach.
"We have to unite," he told the ABC.
"It's the duty of every citizen of Ukraine.
"There are many musicians here, our colleagues from the orchestra and the opera theatre. Everyone is eager to help."
Another volunteer, Dmytro Kyryk, said he'd been working at the beach almost every day, having found a sense of purpose in volunteering that was absent from his day job as a software engineer.
"It helps me because I'm doing something valuable," he said.
Even though his muscles ached from the physical labour, he wanted to do anything to avoid returning to the same habit of "doomscrolling" through news feeds on his phone.
"Being busy and doing something heavy, it actually helps with panic attacks," he said.
Mobilising the many hands of the city
As darkness fell across the city, in an office beneath a building on a quiet street, a dozen women sang patriotic songs as they worked.
"Glory to Ukraine," a woman called out as she entered, using a common refrain of solidarity among Ukrainians since Mr Putin's invasion in February.
"Glory to heroes," the other women replied in unison.
Each of the cramped rooms in the office were filled with volunteers weaving camouflage nets from scraps of earth-coloured clothing.
In the hall, one woman slung over her head a homemade ghillie suit, a type of camouflage worn by snipers, turning whimsically on the spot to show off her creation to the others.
Among the gathered volunteers were academics, architects and teachers. Many hadn't known each other before the war.
One woman, Iryna Stepaniak, a 23-year-old university student, said she hadn't known how to make camouflage nets before she arrived at the office space, but learned quickly by observing other more experienced women.
"This is stuff I can do with my hands," she said. "It's a very small thing, but why not?"
Behind the drive of the volunteers is the widespread belief that their country will soon prevail over Russia.
"We wouldn't be making these things if we didn't believe in that."
