Dream of crash, person, toilet

I dreamt that I was in Brixton near my sister in laws house. I witnessed a really bad car crash. I ran over to the car and was calling for the person saying hello is anyone in there. I didn't hear a voice but kept talking until the person rolled out of the car he was burnt really bad. I shouted for someone to call an ambulance. The scene changed and I was in my sister in laws house but it was bigger that what it is in real life. There was a family gathering, I was greeting people and walking around. Eventually I was going to leave but before that I wanted to go to the toilet. The toilet was downstairs. Upon entering the toilet it was small and there was something blocking the toilet making differcult to access it. I managed to squeeze past and use it. After I used it flushed the toilet it started to flood really bad, the water flowed out and flooded downstairs. I remember feeling a bit embarrassed as I could hear the people outside saying what is happening. I came out and explained what had happened and the dream ended.