Katrina mass graves at Superdome

[snopes]

Comment: After Hurricane Katrina the New Orleans Superdome was used as a
casualty collection point. Many bodies of victims were unidentifiable and
uncollected.

A fried of mine insists that a private contractor was hired to dispose of
the unidentified bodies. He says they simply bulldozed over the bodies,
re-laid the astro-turf, and presto chango, New Orleans had a new field.

Is the newly renovated Louisiana Superdome really an enormous unmarked
grave of unidentified Hurricane Katrina victims?