Customer had a sink that was backed up due to buildup in the drain. She noticed it because she was running water a small drip just so the pipes wouldn’t freeze in all the sinks and overnight. The sink flooded due to having a back up and flooded downstairs into the floor and through the ceiling. Customer already have a restoration company out. I took apart the drain and removed all hair buildup, and gunk that was in the drain, causing the back up. And after testing the drain is working fine now with no backups and no leaks.