To expand on Brian's analogy, even drinking water correctly (as opposed to breathing it) can kill you, if you drink too much. Or add an iodine tablet to it, normally needed to disinfect water, and it can kill you if you are allergic to iodine.
In that older post on dying, students usually either (a)overdid training (b)had underlying disease or (c)did the fall incorrectly in a major way
Beginners usually do not need to worry about (a) because they are so new to it they cannot overexert themselves (they rest while they are trying to figure out how to do things), or (c) because their partners protect them. (b) is self-critiqing.
Most dojos teach beginners how to fall, either in beginners' classes before they mix into main classes, or in their initial visit/first class. And after that the other students usually are very protective of beginners trying to fall.
Once you start training, do not attack any faster or harder than you expect to fall, and make sure your partner knows you are a beginner. As has been said, fall with some control by taking the fall rather than being forced to fall. Pay attention to the ukemi during the demonstration.
As for checking out the nearby dojo, look to be sure students are not all bandaged up, that they are not falling onto/into each other, etc. Does the instructor keep an eye on everyone as they are practicing (would he notice if your partner was about to kill you
Good luck and have fun!