What were the structural causes of the decline and fall of the Roman Empire?

Hi egabb-ga

In the words of the great philosopher-historian, Edward Gibbon:

"The rise of a city, which swelled into an Empire, may deserve, as a
singular prodigy, the reflection of a philosophic mind. But the
decline of Rome was the natural and inevitable effect of immoderate
greatness. Prosperity ripened the principle of decay; the causes of
destruction multiplied with the extent of conquest; and, as soon as
time or accident had removed the artificial supports, the stupendous
fabric yielded to the pressure of its own weight."

General Observsations on the Fall of the Roman Empire in the West by
Edward Gibbon
http://ccat.sas.upenn.edu/jod/texts/gibbon.fall.html

See also:
 
The Fall of Rome by Adrian Dorington
http://ancienthistory.about.com/library/bl/uc_dorrington1.htm

The History Guide
The Decline and Fall of Rome

The Cato Guide, How Excessive Goverment Killed Ancient Rome
http://www.cato.org/pubs/journal/cjv14n2-7.html

All the best,
Alanna-ga

Thank you, this should be helpful.