This is a visual representation of the spark of WW1, the death of Franz Ferdinand.
In March 1914, the archduke of Austria-Hungary, Franz Ferdinand, and his wife decided that they were going to visit the town of Sarajevo, Bosnia.
Gavrilo Princip, a member of the revolutionary movement called 'Young Bosnia' decided that he was going to kill Franz Ferdinand
In May, Gavrilo Princip and two of his associates went to Belgrade, Serbia. They were given six bombs and four pistols by the Black Hand, a secret Serbian society that promoted the liberation of Serbs outside Serbia.
At the end of May, Princip went to Sarajevo, Bosnia to kill Franz Ferdinand. Seven members of Young Bosnia were placed on the town's bridges. A bomb was thrown on their car whilst visiting the town. It bounced off and harmed some soldiers, Franz Ferdinand decided to go back and check on them.
Coincidentally, they parked right in front of Gavrilo Princip. Who put a bullet in Franz Ferdinand and his wife. Ferdinands last words were "Sophie, Sophie! Don't die! Live for our children!"