be unsteady and fall
cause sb/sth to fall from power or authority;overthrow
"The tower of the World Trade Center tumbled after the plane hit it"
A church steeple in flames, finally toppling to earth.
出自： E. Blunden
I lost balance and toppled forward into a..shallow pool.
出自： A. Carter
The..bus caught fire after toppling down an embankment.
出自：New Musical Express