Stop the flow only if safe
If you know where the appropriate shutoff valve is and can reach it safely, turn it off. If you cannot locate the valve, the leak is near electrical equipment or the situation is unsafe, keep clear and seek qualified assistance.
Protect people and important items
Keep children and pets away from the wet area. Move only items that can be handled safely without walking through unsafe water or disturbing damaged structures. Avoid using household electrical equipment in wet areas.
Document the incident
When safe, photograph the affected areas, the source of the leak if visible and any damaged belongings. Keep receipts for reasonable emergency purchases and note when the leak was discovered and when the water was shut off.
Clarify the work scope
Plumbing repair and water-damage cleanup can be separate jobs. Ask whether the provider handles both, what drying and monitoring are included, and what additional work may require another contractor.