Ann: Change in substantial holding from PPT, page-9

I'm not convinced either way at the moment I just saw this on my screen when I did a scan for the largest stocks with the worst debt rating . this is the largest stock with a Bloomberg g10 rating . I don't have a POV either way short or long I am just trying to understand their viability for a long term lease that would require capital investment on my part . No I don't have another rating source and the rating was worse in 2008 (much worse ) and again in 2015 which was marginally worse . does anyone a hypothesis the cause of the stock price collapse ?