* Katniss lost her father in a mining accident orchestrated by the Capitol, and her younger sister Prim was killed by the Capitol's forces during the Quarter Quell.
* Gale lost his mother to the Capitol's bombing during the rebellion, and his younger sister, who is not named in the books, likely starved to death during the famine.
This shared experience of loss and grief fuels their determination to fight against the Capitol and their shared understanding of the cruelty inflicted upon their district and their people. It also contributes to their initial connection and strengthens their bond throughout the rebellion.