AITA for suing my neighbor after their kid trespa*sed and fell into my koi pond?

Dr. Elaine Vance, a specialist in property law and boundary disputes, often notes, 'The presumption of ownership includes the right to exclude. When an owner has taken reasonable steps to secure property, especially high-value assets, liability shifts significantly to the party responsible for the trespass or the failure to supervise dependents.'

The OP clearly established boundaries by installing a secure fence and 'No Trespassing' signs, and they had explicitly warned the neighbor about Timmy previously. Karen’s defense that the pond constitutes an 'attractive nuisance' is generally weakened when the trespasser must actively bypass security measures (climbing a fence) to access the alleged nuisance. Her reaction, demanding the OP pay for medical bills after her son damaged the OP’s property while trespassing, attempts to deflect accountability for both poor supervision and the initial illegal entry.

While the adage 'He's just a kid' often influences social judgments, it does not override legal principles of trespass and property damage, especially when the damage is significant and the trespass was deliberate. The OP’s decision to sue for property replacement and repair costs, which total over $5,000, is a justified professional response to protect a substantial investment that was destroyed due to another party's negligence. The path forward likely involves litigation to establish clear financial accountability for the damage caused by the unsupervised minor.