This is the rule of strict liability or liability without fault.
• The principle in this rule is that a person who for his own purpose brings on his land and collects and keeps there anything likely to do mischief if it escapes does so at his peril and is prima facie answerable for all the damage which is the natural consequence of its escape.
• This principle was formulated in Rylands V. Fletcher where an employer was held liable for the negligence of an independent contractor.
• For this rule to apply, certain conditions are necessary:
o Non-natural user of land
o Bringing, collecting and keeping things.
o Things must be capable of causing mischief if they escape.
o Things must have escaped.
o Interference with the plaintiff’s use of his land.
• Statutory authority: this is a complete defense if the accumulation of the thing was statutorily sanctioned.
• Plaintiffs Consent or benefit: the plaintiff cannot complain of the escape if he benefits from the accumulation or expressly or implied consented to it.
• Contributory negligence: this defense is available to the defendant if they plaintiff contributed to the escape. Its effect is to reduce the amount payable as damages.
• Strangers or third parties: the defendant is not liable if the escape was occasioned by an unforeseen act of a stranger.
Act of God: this defense may be relied upon if the escape is wholly attributable to natural causes. The circumstances must be such that human foresight could not have recognized the escape as a possibility.