House Under Construction

Behind my house in Portugal there is a train line, in which to save time, walking the shortest route would be following the tracks. Me and my friend Fabio would usually walk on the tracks and then cut across an empty lot. One day construction started on the lot we normally used. Diggers opened up this big hole for the foundations and fenced all around it. Lucky for us we still had a narrow path that we could still use to cut from the railway line to the street.
Few months went by, and the construction was almost done. They started to take away the fence around the newly built house. But there was still a gap between the house and the hole they dug for the foundations.
One fine sunny afternoon, after it had rained the night before we were on our way to school, but something had changed... They had filled up the gap. They must have filled it with stones and then finished it up with sand. It looked perfect. Everything was dry. I decided to test it, and without any hesitation, I just put both feet on it. It wasn't a jump, just a tiny leap (of faith). To my surprise, within a split second, I was looking at my friends knees, stuck in mud until half my chest.
I don't remember much of my friend's reaction except for me thinking I'm in sinking sand and shouting for him to pull me out. After that, came the laughter and the walk of shame all the way home, so I could have a change of clothes.