Also known as: abnormally dangerous activity · abnormally dangerous activities · ultrahazardous · ultrahazardous activity
Written by attorneys · grounded in primary & secondary sources — see below
An activity that carries a high degree of risk of serious harm to persons or property. The risk cannot be eliminated by the exercise of reasonable care and the activity is not a matter of common usage. Courts weigh these and related factors to decide whether strict liability applies to resulting harm.
Aisha Ahmed entered a fenced pasture to retrieve her lost hat after seeing a sign warning of an aggressive bull kept by Apollo Energy. The bull charged and injured her. Because Aisha knowingly and unreasonably exposed herself to the known risk from the abnormally dangerous animal, her contributory negligence bars recovery under strict liability.
Audrey Ashton operated a rock quarry next to Alan Ackerman's home and used explosive blasting that sent debris onto his roof. The blasting was an abnormally dangerous activity. Alan can recover for the resulting property damage even though Audrey took every reasonable precaution.
Select any source to read its text and confirm it supports the definition.
Alice Atkins conducted blasting operations that caused rock fragments to land on Abigail Alvarez's adjacent property and damage her greenhouse. The fragments entered the land as a direct result of the abnormally dangerous activity. Abigail can recover for the harm to her land and plants.
Arthur Abrams stored pressurized chemical tanks on his land. During testing a valve failed and corrosive vapor drifted onto Alliance Holdings' neighboring yard. Because the activity was abnormally dangerous, Arthur remains liable for the damage to equipment and plants even though the entry was unintentional and non-negligent.
Apex Dynamics performed aerial crop dusting with strong pesticides near Artemis Logistics' organic fields. Wind carried the spray onto the fields and destroyed the organic certification. Courts consider the high risk of drift, the severity of harm, and the activity's inappropriateness to the location to classify the operation as abnormally dangerous.
Apollo Energy kept a bison herd on its property. A trespasser climbed the fence and was gored. The rules governing liability for harm from an abnormally dangerous domestic animal are the same as those for other artificial conditions on the land.
Courts consider whether the activity involves a high degree of risk of serious harm, whether that risk can be eliminated by reasonable care, whether the activity is uncommon, and whether it is inappropriate to the place where it occurs. Additional factors include the gravity of potential harm and the activity's value to the community.
No. Strict liability applies even when the defendant has taken every possible precaution. The focus remains on the inherent risk of the activity rather than the degree of care exercised.
Contributory negligence is generally not a defense. An exception exists when the plaintiff knowingly and unreasonably subjects himself to the risk created by a wild or abnormally dangerous domestic animal.
Yes. Liability is limited to the kind of harm the possibility of which makes the activity abnormally dangerous. Harm outside that category does not trigger strict liability.
…or (b) unintentional and otherwise actionable under the rules controlling liability for negligent or reckless conduct, or for abnormally dangerous conditions or activities. The defendant argues that the plaintiff has no protected interest in unobstructed access to sunlight. The defendant relies on the common law doctrine of ancient…