Floor 2

Our world was peaceful. All the little kids playing outside, adults by the barbecue talking and enjoying themselves. No, it wasn't perfect. But it was home, it was free. The joy of simply walking to a friend's house or playing a board game with the family was easily accessible. But everyone eventually took it for granted.
That's what started the war in the first place. With how advanced warfare had gotten, it wasn't long before half of the human population was wiped out by biological warfare. No one stood a chance against it. Rulers from every country started to want more. More of everything. Food, money, power, all of it. Then someone decided to act, taking out half of the U.S.A., killing millions.
Luckily, there were a few people left who still used common sense. A team of scientists and engineers came together and created high tech bomb shelters. The buildings were built to hold thousands of people and sustain life for hundreds of millions of years. People were safe again, protected from the remnants of the war and the toxic air.
Eventually, because of how crowded the buildings were getting, they added two more floors and created a system of organization. Each floor signified a different age group. The first floor was the Blossom floor, for newborns to twelve year olds. The second floor was the spring tide floor, for thirteen to thirty nine year olds. Third floor was the forty year olds on up, and was the Golden-age floor.
With this system in place, it cleared up room to maintain the population of the buildings. Along with the new floors, however, came tension and chaos. Everyone wanted to be with their families, and they weren't used to actually working. So, people inside the buildings rose up. Some buildings were destroyed, others remained.