At http://westerndigs.org/epic-fire-marked-beginning-of-the-end-for-ancient… … there is a fascinating story that the mounds (ancient earthen pyramids) and plazas of a typical Meso-american town/city ritual layout, at what is now St Louis in N America, was destroyed by fire towards the end of the 12th century (between 1160 and 1189AD), and then continued in a reduced state until the 14th century – when it was abandoned. These places have a tendency to be ritually brought to a close as a result of a failure of we know not what – and in this instance the medium chosen was fire. This has all sorts of connotations – but as the site is mute we can't say one way or the other. What might have been happening towards the end of the 12th century?
It is suggested that prior to the fiery demise Cahokia practised human sacrifice on a grand scale- and afterwards it abandoned the practise. This is not born out if you read Frazer's Golden Bough as he catalogues several tribal traditions of human sacrifice – possible a garbled account but never the less indicating the practise did not entirely die out. Professor Emilio Spedicato of the University of Bergamo in Italy did suggest at one time there was a bolide event at 1180, but pinpointing its whereabouts in the Pacific – a long way from St Louis. In this instance, no such connection can be made – but it is intriguing none the less.