If you really think about it, it is whoever runs the ninja village's fault for, y'know, making an entire village of murderers.
There was some point at which someone would just die. And with how seemingly low ranking every one of them were besides senpai, they weren't all going to make it.
The context of this chapter could very well be about a group of orphans or a group of sisters which left for the city together and which finally got some education and were starting to build up their own lives, and removing that last panel almost nothing would need to be particularly sad: they already were doing decently well, and if they didn't have such a high-risk job they wouldn't be dying under unfortunate circumstances afterwards.