The building has just been hit by Grad rockets. The columns of grey smoke we saw high in the sky as we approached Popasna erupt from the top floors blackened by the flames and devastated by the explosions. No journalist has ever arrived “In hell, like in Stalingrad. With the Russians bombing incessantly every day I don’t even remember what silence is,” says a Ukrainian drill sergeant. On board colonel Roman’s DIY armored car, we enter the small town of Mariupol, which before the invasion numbered one hundred thousand inhabitants. We are faced with a ghostly sight: the houses have all been ravaged by fighting and the fury of the bombs. There is not a single living soul. The paved roads are pockmarked with craters, debris and the remains of shelling. The only way to get out alive is to cross Popasna at full speed.

Something sharp punctures the back wheel and the two escorting soldiers turn as pale as death. The colonel orders to continue and take shelter under a small railway bridge. Grenades continue to pour down in every direction. The small house just after the bridge no longer has a roof. When we hear the hiss, it means the blow is damn close. The colonel shouts out “Grenade falling!”. The only possible way to take shelter is by crouching behind the armored door. The soldier fumbling at the wheel does the same, extremely fast, like the tire changes at the Formula One pit stops. We continue our mad race across Mariupol, 40% of which is occupied by Russians, until we reach the first outpost in the middle of the rubble. The escort soldier by my side opens the armored door and orders: “Follow me and run, don’t stop.” With our hearts in our throats, we reach a post held by “zombies”. They stare at us like Martians. We do not stop long as rocket launchers set off volleys of Grads and the cannon thunders.

Popasna is strategic to stop the Russians’ advance on Sloviansk and Kramatorsk with the aim of closing the Ukrainian Donbass in a pocket. Over the last hours, at the opposite end of the defense line, further north, Kreminna, has fallen. Russian artillery allegedly hit a car with four civilians on board attempting to escape.

In Popasna, the second outpost is the closest to the trenches, less than a kilometer away. The building has been gutted by heavy artillery fire. A couple of soldiers rush me to see a huge crater dug out by a 250-kilo plane bomb dropped a few hours earlier. Ten meters further and the outpost would have gone up in smoke. A soldier descends into the crater to show me it is twice the height of a man.

In Popasna you need to do everything swiftly, weighed down by your helmet and bulletproof vest. A troop, weapons in hand, runs to the shelter and another soldier leads me between the rail station tracks. The landscape is moon-like: as far as the eye can see nothing is left standing.

Soldiers survive underground, in the foundations of a building shelled repeatedly. Linza, a Donbass battalion veteran explains that “if we’re lucky a grenade goes off every three minutes, but when things get bad, there can be up to five explosions per minute”. Living conditions are extreme and a new unit was force marched into the night to reach the outpost. The soldiers are tense and sweating, nobody jokes as they settle among the rubble. The eyes of those who have been on the front line the longest appear lost in a void as they chain smoke. The unrelenting sergeant admits: “We have already lost a hundred men since the start. Their bones are scattered in the earth between the trenches. It was their sacrifice which saved the city.” He reveals that not all the population is supportive: “Some are waiting for the Russians and have provided indications to help them hit our positions”. He is certain that “hundreds of dead are buried” in the bombed shelters.

Late at night it is time for a unit change in the trenches. The soldiers get their comrades to write their surnames with an indelible black marker on their combat suits at the height of their legs, arms and chest. “That way if we are blown up by Russian artillery and they manage to recover the pieces they can be put in the same coffin,” explains one of the young soldiers ready to die. When it’s time for first team to leave the bunker for a shift of at least three days in the trenches they toss a coin because no one volunteers.

Heading back to Severodonetsk, headquarters of the Ukrainian resistance, we proceed to turn off our headlights as we cross the rubble. The Russians are too close and suddenly two red flashes light up the darkness, followed by the thundering of the armored vehicles canon shots exploding close by. It is not clear whether they were aiming at us or not.