I lived in Nepal for over four years and have been on over a dozen treks in the Himalaya, including two around the Annapurna circuit, so when nearly fifty people died and it was all over the news I had a lot of people asking me about it. I've had fairly lengthy discussions about the region, about what trekking is like in Nepal and I've had a lot to say about how there was no reason this should have happened.
Project Himalaya has written something rather close to my general thoughts on the whole episode that can be read HERE. I really encourage people who are curious about things to take a quick look, because I also won't duplicate many of their points, but will expand upon a few of them.
One of the biggest contributors to the tragedy in my opinion was complacency and a lack of awareness by foreigners as to what they were getting into and very possibly how qualified their guides were. While the above article makes some very well thought out suggestions on things Nepal's government could do to avoid these kind of tragedies, the simple unfortunate truth is that they won't and traveling in a place like Nepal you have to assume that any preemptive safety measures you might assume to be in place either aren't or do not work. This isn't bashing Nepal, it's simply the reality of traveling there. The implication of this is that you need to be responsible for your own safety. This means checking the weather, checking trail conditions, having some basic knowledge about where you are going, and the dangers you might face.
The above list of things you should know are things that many people expect from a guide. Nepal has some of the best and most experienced mountaineering guides in the world, but they are not walking around the Annapurna circuit for $20 a day. The average "guide" most foreigners will work with are not professionals in the common use of the word. They are great people who have learned some English (or appropriate foreign language), can tell you about cultural things you observe, can translate for you, book a room at a lodge up ahead and answer basic questions. They may have even been over the trail a few times. They are however not necessarily trained in any kind of survival techniques, can't read the weather, are not any more experienced with high altitudes than your average experienced climber, and probably aren't very computer or gadget savvy. This means that the instinct to just trust people that you assume to be professional experts would be misplaced, and from a number of stories I've read, it got people killed. I'm no more placing blame on the guides as I am on the people that chose to follow them. I simply stating the conditions that lead to a very bad situation.
There are a lot of questions for me about how things ever got so bad on the Thorung La pass. The pass when approached from the East (the vast majority of climbers come over this route) is ascended from either Phedi (at the passes base) or from high camp (which is about a third of the way up). Some people even stay the night at Phedi and High camp for additional acclimatization. More than a few articles I've read have made a big deal out of the ascent being too fast and people not properly acclimatizing, and the only thing I have to say to that is- if that contributed at all it was because people were too afraid of altitude sickness and made poor decisions over valuing the actual danger it posed. The fact of the matter is that the Thorung La is high, but at 17,500 ft it isn't terribly high. If you've done a rest day in Manang, and then a few more nights before going over the pass most people are going to be absolutely fine. Certainly staying up at the tea shack on top of the pass even if you had gone slightly higher than normally recommended would be safer than braving blizzard conditions in feet of snow. That people were scared enough of altitude sickness speaks well to the campaign to make people aware of it, but also speaks to the possible danger of exaggerating it.
More to the point, as the storm hit hard apparently around noon, I'm unsure why people were up at the pass at this time at all.Internet and phone service is available at Phedi, and I believe at high camp as well. While Nepali weather forecasts are barely existent and lack accuracy often due to what seem like micro-environments where weather varies greatly over short distances, this was a case of a major weather feature that covered a huge area. Anyone paying attention should have noticed this. Even if it was missed, the snow would have hit the southern Annapurnas first and been clearly visible to anyone who recognizes distant falling snow. By the time anyone who had decided to head up from Phedi that morning, by the time they reached high camp I can't understand why they would move on given what should have been clear weather signals. You simply don't attempt high passes in impending inclement weather. I say this as someone who has twice been turned back from passes I wanted to cross due to weather conditions. If you had left from high camp in the morning, I have to wonder why you were still near or at the top of the pass come noon if you had decided to set off. If the trail conditions were so bad that you had barely gotten over the pass in five hours from there, I have to wonder why you would have kept going even an hour in, especially with an approaching storm to the south.
Again I think that many foreign tourists either didn't check the weather or know how to read the signs of what was coming, or relied on a guide that didn't have any clue about the dangers of these kind of storms. What many people don't realize is that many of these guides are not necessarily from the mountains- many are from the lowlands of the Terrai, or grew up in the cities of Kathmandu or Pokhara, and thus don't have any more understanding of mountain weather patterns than anyone else. Even the staff at many of the lodges share this background, because the owners are not always present adn have made enough money that they hire staff from outside to run the business. You simply don't attempt these kind of things in those conditions, and there is no reason someone at some point shouldn't have recognized them.
So what to take away from this. The first thing is that high altitude trekking is an inherently dangerous activity that needs to be approached seriously. Second is that in any place or activity you are responsible for your own safety, but this is especially true in a place like Nepal where there are no functional safety nets. You have to do your own homework; check the weather, learn about the route, and if you're going up into places like this being familiar with a few survival techniques should you get caught out in the elements is probably a prudent thing to do. You also need to really understand that when you are in a foreign country that you can't assume too much, especially you can't assume that things work in anyway similar to where you are from.