In a breaking news story the first thing you need is information. The news wires are a valuable source of initial information but you will also need to make calls, search online and scour social media to add your own verifiable details.
As well as text try to include some images and/or video. These convey far more in terms of realism and emotion than words alone. They can also be detached and shared independently of your news piece, extending the reach of your article.
If you have a quote from an official or a witness, add this to your story as soon as possible in a quote box (your CMS may provide tools for this). Alternatively use a fact box and highlight the key facts in that.