If you fly into something crowded (say a moving train full of people) to die by suicide (自殺), that is going to be suicide by train. Unfortunately, this is a term you should probably be familiar with because it comes up from time to time on the news and around train stations. (Hopefully someday it will no longer be a term you need to know and we can remove it forever.)

The readings come from 飛ぶ, 込む, and 自殺. Combine them together to read this entire word.