Sodom

God was talking to Abraham about destroying Sodom and Gornorrha. Abraham pleaded with God to not destroy the city if he found x amount of righteous people there. So, God agreed to that to show he was merciful and he would not destroy the city for the righteous's sake. Two angels went to Sodom and were met by Lot who let them come to his home and provided him with food. However all the men in the city found out that Lot had two foreign men in his house and they wanted to have sex with those two men. (I guess thats why sodomy is named after Sodom...) Lot however would not let them and offered him his daughters instead which they declined. God decided to destroy the city but he spared Lot and his family. I do not know if God unfairly punished the city because the number of righteous people in the city was not met. If there are only 5 righteous people in a city of 100,000 is it worth saving the whole city instead of just saving those 5?