After Adam and Eve ate the fruit from the tree of the knowledge of good and evil and sin entered the world, bad things began to happen. People began living their own way, they were selfish, they argued and fought and forgot about God who had created them.
God was sorry that He had made man on the earth and decided to destroy all men, women and everything that lived on the earth. But, there was one man called Noah who pleased God.
God told Noah his plan to destroy the earth and every living thing on the earth. God told Noah he should build an ark made of gopherwood big enough to hold him, his wife, his sons, their wives and two of each kind of animal and bird.
So Noah built the ark and once it was finished God sent two of each kind of animal to Noah to go on the ark. Once Noah, his family and all the animals were all on the ark God sent rain on the earth which caused a flood which covered the whole earth for 40 days and 40 nights and all living things outside the ark were destroyed.