What a nightmare, I lived in a building once and it also
had a trash chute and the door hinged down and had
an actuator on it to stop the door from opening all the way down.
You had to drop your trash bags at the top, similar to an old
metal post office box you would find on the street. It was designed
so a child would have a hard time climbing-up in this unit.

It sounds like the boy was looking inside the unit head first
and he lost his balance and went down head first. The inside
of these chutes are very smooth sheet metal and very straight
so the garbage bags will not catch on anything.
I’m sure he passed-out from the velocity of the fall before the impact.

Perhaps they will make a new standard in America for the chutes
and name it after the boy. Very sorry to read this story.

Thoughts and prayers for the family & friends,