Our modern society relies upon complex, modern supply chains for food. How would we cope if they were to suddenly collapse?

It happened almost overnight. Rešad Trbonja was an ordinary teenager growing up in a thriving, modern city, one which only a few years earlier had hosted the Winter Olympics. Then on 5 April 1992, the place he had called home was suddenly cut off from the outside world.

Worst Case Scenario

This article is part of a new BBC Future column called Worst Case Scenario, which looks at the extremes of the human experience and the remarkable resilience people display in the face of adversity.

It aims to look at ways people have coped when the worst happens and what lessons we can learn from their experiences.

What he – along with almost 400,000 other inhabitants trapped inside Sarajevo by the Bosnian Serb Army – could not guess was that it was the start of a nightmare that would last nearly four years. In the Siege of Sarajevo, ordinary residents trapped inside the city would go about their lives to a daily thump of artillery and crack of sniper rifles. Even simply crossing the street or queuing for bread would become a life-threatening experience as the soldiers on the hills surrounding the city took pot-shots at the local populace.

But while the bullets and shells fired into their city were a constant threat, Trbonja and his neighbours faced another, quieter foe from within: hunger.

"The food began to run out almost immediately," recalls Trbonja, who was 19 years old at the time and now teaches school children about the war in Bosnia. "The little bit of food in the stores went pretty quickly and many of the shops were looted. A cupboard and a fridge at home doesn't hold very much when you're feeding a whole family, so it didn't take long for everything to be gone."