Stop the overflow if safe
If the toilet is still filling and you can safely access the shutoff valve, stop the water supply. Avoid direct contact with contaminated water.
Contain the affected area
Keep people and pets away and avoid carrying wet porous items through unaffected spaces.
Consider what materials were exposed
Baseboards, drywall, flooring, carpet pad and cabinetry may respond differently depending on the water quality and degree of saturation.
Drying comes after contamination decisions
The area must still be dried after cleaning, removal and disinfection decisions have been made.
Talk through the situation by phone
Describe the source of the water, the affected area and whether the water is still entering the property.