This all begins in a normal world as if nothing happened, suddendly a gigantic tsunami has appered which left everyone in despair. People cannot go even highter due to the tsunami is bigger than than Burj Khalifa. After the strike, every countries is submerged in a pool of ocean and the people that survives the flood tho. They had to do some survival on their own, in groups or in factions as they used leftover boats or build settlements on their own.