The decline of Rome was due to multiple reasons. War was the main issue. Roman warriors were so powerful that their army took over all the major city states, so the land they owned grew bigger and bigger so it became harder to defend that plot of land. The emperors abused their power and upped the taxes to pay for the army. So the rich got richer and the poor got poorer. Businesses went bankrupt. They bought foreigners and employed poor people to replace the Roman warriors who died in battle. Therefore, the Roman army was full of people who were not trustworthy, and the foreigners ended up turning on them.
Because the emperors like Nero or Caligula abused their power the morals and values that kept Rome together fell. Crime on the streets increased making larger cities unsafe, prostitution became common; the minds of the roman people became infested with sex and violence.
Public health was another issue: the great amount of deaths in the coliseum from gladiatorial fights spread diseases throughout the land. It affected all Romans, rich and poor.
Currency dropped so merchants upped their prices. Eventually people got paid in food or clothes and taxes were paid by fruits and vegetables.
The decline could have been prevented in many ways by: choosing your emperor wisely, not just the one who will work on just war issues; don't invade other lands continuously. They will be in your possession, but you would have to defend them all. Not so good. Clean up after yourself by washing the arena every so often or halt the violence.
