Mountain flying
Sympathy to the families of those involved.
Having flown from Feschiebridge and Aboyne in gliders I learned how unpredictable the conditions can be, outwardly benign on the airfield can be viscous a few miles away a few thousand feet higher. Gliding has the advantage of being mainly club based where pilots are briefed comprehensively by a local expert, often the CFI who knows where the dangerous conditions are likely to be that day.
Gliders are usually looking for Wave to climb but if you get it wrong and fall into the rotor you need to get out fast, with altitude no harm done but lower down deadly, never underestimate changing conditions close to any hills.