Every building older than a century gets called "historic" by someone, and most of them are not. The distinction is between importance and age: a historic event changed something, a historical event merely happened. Journalists reach for "historic" because it sounds weightier, which is precisely why it has been worn thin.
An adjective meaning famous or important in history — significant enough to be remembered.
An adjective meaning relating to the past, or belonging to history. No judgement about importance.
Quick way to remember
Ask whether the thing was important or simply old. Important gets "historic." Old, or about the past, gets "historical." If you can replace the word with "significant" and keep the meaning, "historic" is right.