Can we be sued for loss of income and receive a fine from the fire brigade?

Fire brigades do not impose fines. Courts impose fines. If you are asking if your city, state or nation has a penal law, allowing for a fine, addressing the specific facts of your case, I have no guesses. I do not know every statute in the world. Nor have I read your liability insurance policy. If you are asking if every such contract is the same, they are not. So, you might want to read your's.