It’s impossible to demolish a building by implosion.

The term has been so badly MISUSED so often that some dictionaries will refer to building implosions. NO NO NO, that’s totally wrong. It’s not physically possible.

The ONLY THING that can cause ANY implosion of ANYthing is if external pressure is greater than internal pressure. The inside air pressure of buildings is exactly the same as external air pressure … therefore… NO BUILDING IMPLOSION is possible. 

Buildings simply crumble due to many precisely timed explosions which cause it to fall inward by ordinary gravity, hopefully the desired direction, (inward if done correctly). THERE IS NO IMPLOSION involved.
As you can see, these buildings simply rolled on their side, no implosion. 

THIS is a bubble imploding.  

Bubble in the process of imploding.

A bubble imploding then vanishes to it's natural state.

Example - If you had a freestanding brick wall and set off explosions to make one side of the foundation crumble, the wall would fall in the desired direction (No implosion). If you had FOUR brick walls (like a building) and set off explosives to cause each wall to fall toward the center (like a building being demolished), there is NO implosion of that building (4 walls ) just simple gravity… NO external pressure caused the building to fall inward. It was a simple demolition, gravity, NOT an implosion.
IF you suck all the air out of a pop can, the can will implode because the outside atmospheric pressure will be greater than the inside pressure… THAT’s an implosion.
Heat up an oil drum then seal it airtight and spray it or cool it with cold water, the oil barrel will implode with significant force (LOUD noise from the shock wave). The external air rushes toward the implosion then stops abruptly, causing the noise.
Submarines can implode because the water pressure outside is greater than air pressure inside pushing out.
Hydraulic cylinders can cause implosions in the hydraulic fluid (Can actually destroy equipment due to the "slamming" (Jet) effect when the bubbles collapse=implode)
Ultrasonic vibrations can cause implosions in liquids and the friction of the collapsing bubbles can cause enough heat to boil the water, or
cavitation due to or ultra-high speed underwater propellers, can cause temporary air bubbles which instantly implode causing an "explosive" noise that sounds like boiling water. The bubbles implode so rapidly they create destructive shock waves (noise).
FINAL NOTE: "A BUILDING WILL NEVER IMPLODE" (It’s physically impossible).
Imploding pop can
Imploding oil drum
http://www.youtube.com/watch?v=JEqjIHclzp8&feature=related http://www.fas.harvard.edu/~scidemos/ThermalPhysics/55GallonDrum/55GallonDrum.html
 An example of a misuse of the word Implosion. but...see box "A real implosion".
If you like to see buildings here are Many demolitions (but not a single implosion).
Building rolls over on roof