Massachusetts General Laws Part I. Administration of the Government (Ch. 1-182) Ch. 48, § 3

Three or more firewards present at a place which is in immediate danger from fire, or if there are not three of them present the selectmen or the mayor and the aldermen present, or in their absence two or more of the civil officers present, or in their absence two or more of the chief military officers of the place present may direct any building to be demolished if they deem it necessary to prevent the spread of the fire.