Summary of Trimarco v. Klein, 56 N.Y.2d 98, 436 N.E.2d 502 (1982)
Facts: P a tenant and D his landlord. P was injured while he was taking a shower and the glass shower door shattered. P sued D for negligently not installing shatterproof glass shower door. P introduced evidence showing that it was common practice among landlords to install such doors in the apartments.
Procedure: At trial, judgment for P. Ct. of Appeals reversed ruling that D had no duty to change door absent any notice of danger from P or from other similar accidents in the building.
Issue: Can D be held liable for ignoring the customary practice among the landlords?
Rationale: According to the ct., customary practices can be used to determine whether D used due care or whether he was negligent. These customary practices need not be universal, and it is enough that these practices be fairly well defined and in the same calling or business so that the actor may be charged with knowledge of it or negligent ignorance. Furthermore, the jury has to determine whether these customary practices are reasonable. In the current case, P introduced evidence that shows that it was a customary practice among landlords to install shatterproof shower doors. [case still remanded on some other grounds]