Wisconsin Statutes Emergency Management (Ch. 323) § 323.44. Public shelters

(1) Any person owning or controlling real property who voluntarily and without compensation permits the state or any of its political subdivisions to inspect, designate, and use the whole or any part of the real property for the purpose of sheltering persons during a disaster, an imminent threat of a disaster, or a related training exercise is immune from civil liability for negligently causing the death of or injury to any person on or about the real property while it is being used to shelter persons during a disaster, an imminent threat of a disaster, or a related training exercise, if the owner or controller has complied with sub. (2).

(2) Any person owning or controlling real property who gratuitously grants the use of that real property for the purposes stated in sub. (1) shall make known to the licensee any hidden dangers or safety hazards which are known to the owner or occupant of the real property that might possibly result in death or injury or loss of property to any person making use of the property.