Drain line was stopped up causing water to come in through her kitchen ceiling. Cleared the drain line with nitrogen & it stopped over flowing. Tenant was still concerned because it was still dripping but mentioned it could be from a puddle where the leaking was coming from, so I made a small hole into the ruined sheetrock & that was the case. Couldn’t see drain line from the hole so it’s running between the ceiling from the first floor & the floor from the second floor. Might need to reroute the drain line once the ceiling is repaired as the sheetrock is ruined & needs to be replaced.