What are the facts?
Ploof, with his wife and two minor children aboard his sloop, was sailing on Lake Champlain when a sudden, violent storm arose, creating imminent danger to life and property. To avoid the peril, Ploof moored his vessel to Putnam's private dock. While the storm continued, Putnam's servant (acting within the scope of his employment and authority over the dock) intentionally unfastened the sloop's moorings, thereby casting the vessel back into the storm. The sloop was driven ashore and wrecked; Ploof and his family suffered personal injuries and damages to the vessel and its contents. Ploof sued Putnam, asserting that the servant's act was wrongful given the necessity that compelled Ploof to use the dock.
What is the legal issue?
Does the doctrine of private necessity privilege a person to enter and remain on another's property to avoid imminent serious harm, thereby making it wrongful for the landowner (or the landowner's servant) to eject the person, and rendering the landowner liable for resulting injuries caused by such ejection?
What rule applies?
Private necessity creates a privilege to enter and temporarily remain on another's property when reasonably necessary to avoid serious harm to human life or significant property interests. This necessity excuses what would otherwise be a trespass and imposes a correlative duty on the landowner not to expel or interfere with the entrant while the necessity persists. An owner (and the owner's agent or servant) who unreasonably ejects a person acting under necessity is liable for resulting harms. Under respondeat superior, a master is liable for torts committed by a servant acting within the scope of employment.
What did the court hold?
Yes. The storm created a necessity that privileged Ploof to moor at the private dock. The servant's unmooring of the sloop during the emergency was wrongful, and Putnam is liable for the injuries and damages proximately caused by his servant's act.
What is the reasoning?
The court recognized long-standing common-law principles that necessity may justify conduct that would otherwise constitute a trespass, especially when human life is at stake. The emergence of a sudden and violent storm presented an imminent peril to Ploof and his family, and mooring at the nearest available dock was a reasonable and proportionate response. Because the entry was privileged by necessity, Putnam had a correlative duty not to interfere with Ploof's use of the dock while the emergency persisted. By ordering or allowing his servant to unfasten the sloop—an affirmative act that exposed Ploof and his family to the very danger they sought to avoid—Putnam breached that duty. The court emphasized that necessity does not license the owner to take steps that aggravate the peril; rather, it obliges the owner to tolerate the temporary intrusion. Furthermore, the servant acted within the scope of his employment in managing the dock, so Putnam is vicariously liable for the servant's wrongful conduct. The injuries and property damage were the natural and proximate result of the wrongful unmooring, supporting liability.
Why is this case significant?
Ploof v. Putnam is a cornerstone of the private necessity doctrine. It clarifies that necessity privileges emergency entries onto private property and imposes on landowners a duty to refrain from active ejection while the danger persists. The case is frequently paired with Vincent v. Lake Erie Transportation Co. to illustrate that private necessity is an incomplete privilege: it excuses the trespass, but if the entrant causes damage to the property while protecting his own interests, compensation may still be required. Ploof thus frames essential questions about competing property and personal safety interests, proportionality, and the scope of landowner obligations during emergencies.
What is the difference between private necessity and public necessity?
Private necessity arises when an individual invades another's property to protect private interests (e.g., saving oneself or one's property from imminent harm). It privileges the entry and bars liability for the trespass itself but may still require compensation if damage to the property occurs. Public necessity involves actions taken to avert a public disaster (e.g., destroying property to stop a fire's spread) and typically provides a broader privilege that can preclude compensation for property damage. Ploof concerns private necessity.
Did Ploof owe Putnam compensation for using the dock?
No compensation was at issue in Ploof because the plaintiff's use did not damage the dock; the harm flowed from the defendant's wrongful unmooring. Ploof establishes the privilege to enter and remain. Whether a trespasser must pay for damage inflicted while exercising the privilege is more fully addressed in Vincent v. Lake Erie Transportation Co., where the court required compensation for dock damage caused during a storm.
Why was Putnam liable for his servant's actions?
The servant managed or controlled access to the dock and acted within the scope of his employment when he unmoored the sloop. Under respondeat superior, a master is vicariously liable for torts committed by a servant in the scope of employment. Because the servant wrongfully interfered with a privileged entrant, Putnam bore liability for the resulting harms.
What level of danger is required to invoke private necessity?
There must be a reasonable belief in imminent and serious harm to human life or significant property interests, and the response must be proportionate. In Ploof, a sudden, violent storm presented an immediate peril, and mooring at the nearest dock was a reasonable means of avoiding that harm.
Does private necessity create a duty for the landowner to aid the entrant?
Ploof does not impose an affirmative duty to provide aid; rather, it imposes a negative duty not to interfere with the entrant's reasonable, necessity-driven use. The landowner must refrain from ejecting or obstructing the entrant while the necessity continues. Some jurisdictions recognize additional duties under particular circumstances, but Ploof's core holding is a duty not to expel.