The basement in our rental house is flooded. Theres no visible pipe or anything where the water has come from. There are "particles and pieces" that have floated out that are substances which would have passed through a toilet including paper; yet no visible way that they could have gotten to where they are now in whole form. The drain in the basement floor isn't draining, and the grate wouldn't allow the larger floating "items" to have surfaced from below. Not being a plumber or having dealt with floods before, I am at a loss at what to do next.