What was the event in Chapter 1 for lord of the flies?

A fair hair schoolboy is in a jungle. He is joined by a fat boy and their conversation reveals that they are English and that they were being evacuated on board a plane when it was attacked and their passenger tube was jettisoned and landed on a tropical island. Apparently the tube was dragged out to sea by a storm with some boys still on board. The fair boy, who's name is Ralph, heads for the beach where he takes all his clothes off and stands on his head with the pleasure of being on a tropical island. He goes for a swim. The fat boy reveals that he was nicknamed Piggy at school, he can't swim because he has Asthma, he also wears thick spectacles. Ralph finds a shell called a conch in the lagoon. With Piggy's instructions he blows it and lots of other boys appear from the jungle and join them, including a pair of twins and a choir led by a red haired boy called Jack. The boys range in age from around 6 up to 12. When they realise that there are no adults Jack wants to be in charge but the boys have a vote and elect Ralph as their leader. He says Jack is still in charge of the choir and Jack says he wants them to be hunters. Ralph decides to settle for certain if they are on an island by climbing the mountain which is close by. He takes Jack and a younger boy called Simon with him. They climb the mountain and see that they are on an island and head back to tell the other boys. On the way back they see a piglet and Jack has a chance to kill it with his knife but he hesitates and it escapes.