What is a Wrecking Machine?
A wrecking machine probably refers to a type of demolition equipment consisting of a wrecking ball suspended from a crane. The ball is continuously smashed into structures to destroy them by reducing the structure to rubble.
What might a person use a wrecking machine for? Please list a few options.
A person could use this to demolish a building or any other structure.
Examples of what could be demolished include:
* Towers or chimneys
* Houses
* Apartment blocks 
* High rise structures like sky scrapers
* Commercial buildings like factories