Preserve the useful detail
Note one or both bowls, appliance discharge, disposal behavior, other-room drainage, and the exact order in which water rises.
The decision on display
Do not transfer the hazard
Turn off and avoid reaching into a disposal. Do not combine cleaners, add water, or plunge against an appliance connection.
Make the proposed work comparable
Separate disposal work, trap access, branch clearing, camera conditions, cabinet protection, reassembly, and appliance drain testing.
CURRENT PRIMARY SOURCE