According to Coast traffic boss Emmanuel Okanda, the child fell to the ground from the moving bus and was rolled over.
The kid was attempting to save his water bottle and bag which fell through a gap in the floor of the bus that had rusted.
Okanda says they have arrested the driver of the school bus as they launch investigation.
An eyewitness who posted the photos said the bus floor was rusted and weakened thus after a bump the child fell on the ground through the hole and was crushed by the back tyres.
More photos below…