Well, three years ago, I fell on the stairs. Over time, they became "off-level". One morning, it was raining slightly, and I was holding my grandson's hand (he was just 12 months old), and my shoe slipped on the uneven step. I had a bad fall. My grandson did too, but he only fell ON the step. I had a nasty bruise for weeks. We added a 2x4 where I could at least hold something and the stairs were leveled within days. My husband also bought that anti-slip paint and painted all the steps with it (it is like paint with sand in it).