The Domino Effect

Dominos are square-shaped or rectangular-shaped tiles that can be made to stand on one end and place near each other in long lines so that when the first domino tile is toppled, it topples the second one which in turn will topple the next and so on until every tile in the line is toppled.

​Usually, all the domino tiles
have the same size and weight
to ensure each of them topples 
up to the last one in the line.
By analogy,
this is called the domino effect
or a chain reaction
where one incident 
sets off a series of other incidents
until everything becomes a disaster.
Think about what a tiny flame 
from a match stick can do
to engulf the whole house on fire,
as what usually happened in fire emergencies.

Interestingly,
there is a domino show
that involves tiles of varying sizes
that still do the same toppling chain,
the first of which is very small or tiny 
and the last one is very big and heavy.
Never thought this could be possible.