If an employee of a retail establishment permits a person to use the establishment's toilet facility, under the requirements of s. 146.29, the employee and the establishment are immune from civil liability for the death of or injury to the person, or an individual other than an employee who accompanies the person, that is caused by or during the use of the facility, unless the death or injury was caused by a willful or wanton act or omission of the employee.
Wis. Stat. § 895.512