Like most accidental deaths that occur in nature, it appears that inadequate decision-making, or inadequate information to guide decision-making, was a major factor.

Make a bad enough decision, or a series of bad decisions, and all the equipment you can carry may not save you.

From the initial scanty information provided, it appears they violated a fundamental rule of outdoorsmanship - check the forecast and keep a close eye on the weather.

Outdoorsmen should have good judgment, but where does good judgment come from? Experience. And where does experience come from? Mostly from bad judgment!

Jeff