When more than one fixture backs up—especially a basement drain, toilet, and tub—the shared drain or building sewer becomes more plausible than a single clogged trap.
First, reduce the damage
Stop running dishwashers and washing machines. If sewage is present, keep people and pets away and avoid electrical hazards.
Record the pattern
Note which fixture moved first, whether backup followed water use, and whether the problem affects the lowest level. These details are more useful than guessing at a cause.
What a useful inspection should show
Ask for the camera location, footage or stills, approximate distance, pipe material, and the exact defect tied to the recommended repair.
Homeowner safety note
Do not enter contaminated spaces or attempt work that exposes you to sewage, unstable excavation, pressurized lines, or electrical hazards.