Why was the Colosseum destroyed

The Colosseum, called the ancient Romans "Amphitheatrum Flavium", was built in 72 AD by Emperor Vespasian and inaugurated by his son Titus nell'80
The building was occupied from since the Nero Palace, the Domus Aurea, built after the great fire of Rome in 64, which was supposed to be enclosed a valley between the hills of Velia, Palatine, Celio, Oppio and Fagutale and was surrounded by a river crisscrossed, which ran along a route that roughly follows the current route from San Gregorio towards the Tiber.
The presence of the pond was abundantly used to save foundations, made of travertine columns resting on a ring of continuous concrete, spaced only by a few fognoli for scrolling the groundwater that would otherwise flood the entire area.
nearby was a colossal statue of Nero, from which legend has it that the name Colosseum derives. After killing the statue of the emperor for Sol to show the god of the sun was rimodellata, add the corresponding solar corona. The colossus was then moved from its original location to make way for the Temple of Venus and Roma under Adriano. The location of the statue's huge pedestal after the move is currently marked by a modern base in tuff.

the original structure had to be very precise: for the reigns of Vespasian and Domitian there are notes in the Colosseum of naumachie, that is, naval battles. This may mean that originally the bottom of the Colosseum had a large amount of water than sufficient to allow, perhaps even just to hold the original pond born in the house of Nero.
The large audience founding, crown-shaped elliptical, had a thickness of thirteen meters and in his internal engineers ricavarono Roman a series of funnels for the drainage of rainwater. As soon as the high monument, all'interramento areas went up on the current plan of the square around which was then leveled. The tavolati huge area of ​​the arena poggiavano on a series of parallel walls that were derived from slots that were used to transport the wild animals and gladiators. Portal for the underground of the Colosseum, lit by torches and oil lamps, accessible through four corridors along the axes of the building, so that it was possible to reach these environments also by car. The cripotoportico connected north of the underground to the Colosseum with the Ludus Magnus (the nearby gladiators barracks) where there was a series of buildings that opened on a courtyard with gym discovery of the elliptical shape, a miniature amphitheater house. From the subway, on the stage where the Kaiser attends the shows, there are stairs that allow Kaiser a direct link on the stage. From this part hypogeum another corridor, illuminated by skylights, which originally had a coating of marble and decorated with stucco time paintings, was used by emperors to enter the Colosseum without being visas.
Inside the auditorium with the steps for the seats of the spectators was divided horizontally into five sectors (maeniana), reserved for the different categories of public sector lower, reserved for senators and their families, had steps comprehensive and deep that housed wooden seats (subsellia) ; This was followed by the maenianum primum, with eight marble steps, maenianum secundum, divided into imum (lower) and summum (higher), still with marble steps and finally the maenianum summum, with over eleven steps inside the wooden veranda that crowns the auditorium (porticus in summa cavea): the remains of the architectural latter belong to the redesign of the age Severiana or Gordian II.
The different sectors that were separated by high podiums (precinctio) where the doors opened (vomitoria), protected by marble barriers (dating back to the restoration of the second century AD, steps are engraved on the indications of the posts and balustrade on the pedestal the Names of the attending senators to whom the seats were reserved were lower.
Spectators reached their place to enter the arcades of their confidential. Each of the 74 arches open to the public has been identified by a number engraved on the keystone, to allow onlookers. quickly reach its place

over the years, fires, earthquakes and man inflissero quite severe blows at the Colosseum:
In 217 dc a fire destroyed the above structures, the building was restored by Eliogabalo and Alexander Severus, and was reopened in 222 without jobs being terminated. There were other fires in 250/252 and 320 that created damage to the Colosseum and there were other reconstructions under Constantine and King Odoacer (Odoacre, the first barbarian king of Rome) in the 476 to 483 dc
After the fall of the Roman Empire there were other works in rehabilitation after another earthquake occurred around 484 or 508. At some point the great Flavio amphitheater was abandoned and in the sixth century the area used for burial; later used as a residential building.
Nell'alto the Colosseum was medieval fortress of Frangipane and Annibaldi until 1312, when the Emperor Henry VII intervened that the riconsegn? Senate and then to the Roman people.
The earthquakes of 1231 and 1349 brought other damage to the Colosseum, which is now again in ruins. The sad fate had a marble quarry used to construct new buildings under the most famous, Palazzo Venezia and stationery. The blocks were removed or these were used by natural disasters killed travertine to build Palazzo Barberini in 1703 and the port of Ripetta. It was said that famous was part of a description of "looting" the Colosseum, saying: "Quod fecerunt barbarians not, fecerunt Barberini" (What the barbarians did not, Barberini did).
During the Jubilee of 1675 it assumed the character holy place in memory of the many Christian martyrs here condemned to torture and consecrated in 1744 Pope Benedict XIV of the Passion of Christ and there were the 15 steps to be built in the Way of the Cross, in memory of Christian martyrs killed in the arena.
As a result of the structural damage the first restorations came: spurs that stopped the ends to support the facade were built in 1807 by Raffaele Stern and in 1827 by Luigi Maria Valadier, the new work in the structures ricompose already collapsed. Other restorations inside there were between 1831 and 1846. At the same time the monument dall'interro began to loosen with the excavations directed by Carlo Fea in 1811 and 1812 and those directed by Peter Rosa (1874-1875). Hotels in 1938 and 1939, structures against the arena were completely excavated, some of which were changed through reconstructions.