What do you do when your sister is hysterical because Dad messed up again?

What do I do when my sister is hysterical on the phone because my dad messed up again as he so often does. He blocked up the toilet and she had water running almost into her bedroom and had to clean up the mess after him yet again on her empty stomach early morning. Shame, she just said earlier that he is more passive and she can cope better now with him. And 10min later, she is hysterical. She has mopped up after him too often. Worse, we grew up with him visiting part-time and caused a lot of unhappiness in the home with my mom, so we feel that we don't mind looking out or after him, so to speak, as there is no one else to do it, but when you sit with a faeces problem first thing in the morning, or anytime for that matter, its really tough. Anyone else in a similar situation?