What is a prerequisite for liability according to traditional principles of Rylands v Fletcher?

The principle of liability under Rylands v. Fletcher is fundamentally based on the idea that a person who brings onto their land something likely to cause harm if it escapes is liable for any damage that ensues if that thing does escape. Therefore, the prerequisite for establishing liability involves the actual escape of the harmful substances onto neighboring property.

This principle rests on the notion of strict liability, which does not require proof of negligence or carelessness on the part of the defendant but instead focuses on the nature of the activity and its potential risks. The escape of these materials signifies that something hazardous has moved from the defendant's control to a surrounding area, leading to potential harm to others. In this context, the law seeks to encourage individuals to act with caution regarding potentially dangerous activities on their property.

Other options suggest requirements such as proving recklessness, having ownership of the harmful material, or establishing a clear act of negligence, which do not align with the foundational aspects of the Rylands v. Fletcher rule. The focus is not on the defendant's state of mind or their maintenance of the substance, but rather on the consequences of the escape itself.