While we are awaiting more information about this tragic accident, there is already one lesson that can be learned from this story: people who think that a helicopter will arrive half an hour after activating distress call from their PLB should rid themselves of this delusion, and the sooner the better.
Even if a helicopter arrives it is not certain that they will be able to pick up the caller - I highly recommend this winter rescue story on Rosalie Peak in Colorado:
http://www.summitpost.org/rescue-on-...19-2011/701157