Why the the cones remain in equilibrium before toppling-what disrupted the equilibrium condition later

Water bucket damper at splash pad

After watching the following clip, discuss why the cones topple and dump the water after the water in the cones reach a certain level.

Discuss

i) why the the cones remain in equilibrium before toppling,

ii) what disrupted the equilibrium condition later
The answers to the above questions must be supported with relevant sketches, free body diagrams, and static equilibrium equations