To be a bit more accurate..... An unknown number of master recordings was destroyed in the fire. It was probably around 175,000 masters. "500k songs" is an estimate. The best source on this is the NYT article: The Day the Music Burned
So UMG got to collect insurance on a bunch of stuff they essentially had already written off anyway. Nothing fishy about this at all...
So, it took them 10 years to come clean on this? Just enough time to get the lawyers lined up. Maybe not on the level of the burning of the Library of Alexandria, but still...kinda hinky.
Further coverage by the Times, following up on ClusterFlux, above: Here Are Hundreds More Artists Whose Tapes Were Destroyed in the UMG Fire Musicians Mourn the Fiery Destruction of Their Recordings: ‘I Think They Are Gone Forever’