Everyone has their own definitions of tragedy. People have different views and opinions on things and that's totally okay. My own definitions of tragedy is something horrible that happened. Things like 9/11, the LA terrorist attacks, hurricanes, earthquakes, ect. Tragedy and horrible are synonyms with they own specific definitions. The thing about tragedy though, is that their is multiple meanings to it. The mother meaning behind tragedy is a form of art that people enjoy watching, listening, or reading. It's a genre of literature that has been passed on from generation to generation.
We as a human society love watching tragedy. Not the horrific kind, but the form of art. It's been around us for centuries and many plays, movies, music, and tons of other media has tragedy. It's mainly just a drama that people watch for pleasure. Why do we find pleasure in watching people suffer? I think the reason we seek pleasure in tragedy is because we see things in plays and productions and find that sometimes we can relate. We feel are those charters and we sympathize because it can be really emotional.