There are simply not enough facepalms on the internet to explain the collective stupid of this story. This is the closest I could find.
The bonus is that this story comes out of Changsha, so that should prepare you.
According to the China Daily, an "accident" at a Changsha primary school resulted in injuries to 33 students serious enough for the students to be hospitalized. What massive accident could have lead to this catastrophe? According to the article, "a group of students went to the playground during their break but found that the playground was flooded, so they decided to return to their classrooms.
When they were climbing the stairs they encountered another group of students coming down. In the ensuing confusion, some students fell, were stepped on and suffered injuries."
There you have it. Two groups of students using a single staircase at the same time can result in mass casualties in China. You have been warned.