That story had quite a discussion on another board. Very lucky to have others nearby that got a SAR helicopter in quickly.
The below is a snippet from a web feature for one of the 6 High Sierra backpacking trips I did this summer. It relates how when I could see a violent storm imminent, that two groups moving up a trail about a modestly exposed sparse timberline zone, were unconcerned even after I gave each a solid warning. As a decades old backpacker, have seen not a few people continuing up towards dangerous ridge lines and peaks while I was hurriedly escaping in the other direction downhill. My career is in electronics, have a solid physics background, and have read a few books on lightning phenomenon. Obviously there are many ordinary people that are rather clueless about lightning dangers and that includes fair numbers of mountain enthusiasts like peak baggers that ought to make it their business to understand.
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About 10am, the strongest thunderstorm of my trip moved over the canyon. Because of the towering canyon walls with storms moving in from the south southeast, it was difficult to see what was coming beyond a few minutes however nearing thunder gave me an earlier warning. As it began to rain lightly, I scurried back towards my camp. At that time I passed a young woman backpacking with a dog moving up the trail and warned them a strong storm as I pointed up south would quickly be on top of us but she seemed unconcerned, set on reaching the pass, about 1.5 miles distant. Just a small ways behind her, I warned a group of 2 couples likewise and they also seemed unimpressed despite the fact heavy rain made views of the south canyon walls blurry a short distance away. Neither group had pack rain covers on their backpacks and all were wearing shorts and t-shirts
About 30 seconds later, I reached my tent and dove in as heavy rain suddenly arrived. Looking out my tent, I could see both those parties only part way up to the knee above camp getting hammered. All of them were suddenly in a panic moving further above out of my sight as monstrous lightning bolts blasted right above. Both groups were obviously novices without much experience but I had to shake my head the way they ignored advice even though it was all so visually obvious. Here in California, thunderstorms are rare in our urban areas so many city people are unfamiliar with what storms look like and how violent they can be with heavy rain that can soak a person in just a few tens of seconds. Upper North Fork of Bishop Creek Canyon with massive towering rock walls is one of the most ideal locations in the Sierra for experiencing thunder echoing loudly and was it impressive! A half hour later after rain stopped, I climbed up the trail and saw the gal and dog stumbling out of some trees where she had managed to put a pack rain cover on her pack but was now hand carrying another clump of something in a large bag, no doubt the result of an emergency digging into her pack for rain gear.