Stop the source when it is safe to do so
If the water is coming from a plumbing fixture or supply line and you can safely reach the shutoff, stop the flow. Do not enter standing water when electrical hazards may be present, and do not handle contaminated water without appropriate protection.
Separate emergency actions from restoration decisions
The immediate goal is to reduce additional damage and establish safe conditions. Extraction, drying, material removal, cleaning, and reconstruction should be based on the source of the water, the materials affected, and how long they have remained wet.
Create a simple record
Photograph affected rooms before moving items when possible. Note when the loss was discovered, the suspected source, and any actions already taken. This record is useful for contractors, property managers, and insurance conversations.