• This rule is to the effect that a person who for his own purpose brings and keep things capable of causing mischief is they escape is prima facie answerable for all the damage which is the natural consequence of their escape.
• This is the rule of strict liability or liability without fault.
• The rule was enunciated in Rylands V. Fletcher where an employer was held liable for the negligence of an independent contractor, he had engaged.
Defences to the rule:
• Contributory negligence: this defence can only be relied upon if the plaintiff contributed to the escape.
• Plaintiffs benefit/consent: if the plaintiff consented to the bringing of the thing or benefits from it, an action against the defendant for its escape is unsustainable.
• Acts of a stranger: this defence is available if the escape is occasioned by the unforeseen acts of a third party.
• Statutory authority: the defendant has a complete defence if the accumulation is authorized by an act of parliament and he acted in accordance with the provisions of the Act.
• Act of God: this is a defence where the escape is wholly attributable to natural causes without human intervention and no human foresight. Could have recognized it was a possibility.