: The likely reason for the flooding (e.g., burst pipe, open tap in Apt #XX) and the presumed responsible party.
Акт о заливе квартиры: правильное оформление, образец
: A detailed list of affected items, including walls, ceilings, flooring, furniture, and electronics. Specify the extent of damage (e.g., "water stains covering 3sqm of ceiling").
: Full names and positions of representatives (e.g., from the management company), the property owner, and ideally the neighbor from the suspected source apartment.
This document fixes the fact of leakage and identifies damage to property. It should be drafted within of reporting the incident.