This topic is the stuff of entire books, entire academic careers. One must remember a couple of things about the Western Empire - Rome had already been sacked by the Visigoths under Alaric in 410 some sixty-six years before the nominal "fall" under Odoacer. Both of those leaders considered themselves Romans by virtue of service, which was the original requirement for Roman citizenship back in the long-gone (and highly romanticized) days of the Republic. By that measure they were better Romans than the inert sloths populating the city.
Rome, and the Roman mob, had become so entirely dependent on external sources for its very bread that when the grain fields fell to the Vandals and Ostium was cut off from the city, the thing was over no matter what happened at the gates. And not much had happened at the gates since the times of Hannibal.
The focus of activity stayed away from Rome until Justinian sent first Belisarius, and then Narses, to take the place back from the Goths. It ended up in the hands of a strange sect called the Christians, but I don't know whatever happened to them...
Well, Rome had been in the hands of Christians for well over a century by then. Both the Byzantines attacking Rome (including Justinian, Belisarius, and Narses) and the Goths occupying it (including Odoacer and his predecessor Alaric) were Christian, as were the Western Roman emperors from whom the Goths took the city.