Overseas Tankship (UK) v Morts Dock and Engineering Co (The Wagon Mound) (1961)

Overseas Tankship (UK) v Morts Dock and Engineering Co (The Wagon Mound) (1961)

Facts: Due to the defendants’ negligence, oil was spilled and accumulated 
around the claimant’s wharf. The oil ignited and the wharf suffered 
fire damage.

Held: The defendants were held not liable since, while damage to the 
wharf by oil pollution was foreseeable, damage by fire was not.

Hughes v Lord Advocate (1963)

Facts: The defendant telephone engineers left an inspection hole covered 
only by a tent and surrounded by paraffin lamps. A child claimant 
was badly injured when he fell down the hole carrying a lamp which 
exploded on impact causing a fireball.

Held: The defendants were liable as they should reasonably have 
foreseen that a child would be attracted by the lamps and might be 
burned when playing with them. It was irrelevant that they could not 
have foreseen the explosion or the severity of the burn damage.

Sir in the above 2 scenerios, I did not understand that why defendant was not liable in wagon mound case, and why defendant
was liable in Hughes V Lord advocate case?