Why was Okonkwo exiled in ‘Things Fall Apart’?

Okonkwo was exiled because his gun exploded at a funeral ceremony, killing the sixteen-year old son of Ezeudu (the man whose funeral occasioned the ritual.) Even though the young man’s death was clearly an accident, it is still a crime, and a very serious one, because the deceased was a clansman. Because the weapon in question belonged to Okonkwo, he is deemed responsible. So Okonkwo is forced to leave the village for seven years. As an additional ritual punishment, several men destroy his houses and kill his animals. Okonkwo and his family proceed to Mbanta, a village not that far away. When he finally returns, he discovers that much has changed in the village.