When I was about 2 yrs old, we lived on the second floor of a duplex. I was sitting out on the balcony playing, then went into my room.
My mum asked my older sister to go and check on me, thinking I was still outside.
My sister went out, then came back and said, "Mummy! Marky's splatted all over the sidewalk!"
She got her ass whipped for that.