Wis. Stat. § 114.05

The liability of the owner, lessee and pilot of every aircraft or spacecraft operating over the lands or waters of this state for injuries or damage to persons or property on the land or water beneath, caused by the ascent, descent or flight of such aircraft or spacecraft, or the dropping or falling of the aircraft or spacecraft or of any object or material therefrom, shall be determined by the law applicable to torts on land, except that there shall be a presumption of liability on the part of the owner, lessee or pilot, as the case may be, where injury or damage is caused by the dropping or falling of the aircraft or spacecraft or of any object or material therefrom, which presumption may be rebutted by proof that the injury or damage was not caused by negligence on the part of the owner, lessee or pilot and the burden of proof in such case shall be upon such owner, lessee or pilot to show absence of negligence on his or her part.