The saddest thing is that this death was absolutely preventable.

The Infantino SlingRider and similar duffel bag style carriers, when used as directed, are inherently unsafe because they a) push baby's chin towards the chest, thus increasing the risk of positional asphyxia, and b) enclose the baby in fabric, thus increasing the risk of rebreathing.
Infantino was notified as far back as October 2006 about the problems with its design, and chose to do nothing. Nor did the CPSC take any action when provided the same information.
There are confirmed deaths of babies in good brands of slings as well -- it's all too possible to use a great sling unsafely. It's not the sling design per se but its unsafe use that puts baby into a chin to chest position that's dangerous.
I've just started a Facebook fan page on babywearing safety that's intended to provide information on the risks of dangerous designs and unsafe wearing positions, as well as safe babywearing positioning information:
http://www.facebook.com/BabywearingSafety