I remember being a little kid staying up late to watch the Niners-Raiders game and seeing the McCallum injury live. I can still remember the whole play and the aftermath, with Ken Norton laying beneath McCallum until the trailers got McCallum stabilized to the point where they could grab Norton and slide him out from underneath, since McCallum could not be moved at that point.
Easily one of the most grotesque injuries I have ever seen in any sport.