Complex sentence: The Dayton Gems, a minor league ice hockey team based in Dayton, Ohio, began with a bang in the fall of 1964 when the lobby of their new arena, Hara Arena, had a natural gas explosion.
Split into simpler sentences: The Dayton Gems, a minor league ice hockey team based in Dayton, Ohio, began with a bang in the fall of 1964. The lobby of their new arena, Hara Arena, had a natural gas explosion.