As phorum_junkie said ->

"Just thank your lucky stars the charger just failed" relatively safely.

"they can actually fry your computer or cause fires or electric shock."  Or even electrocution.

"You should never buy a laptop charger from anyone except an authorised re-seller of the brand you are buying for"

"and you should always buy from a reputable B&M store so that if it does not just fail but cause damage you can actually get some redress."

And I will add - look for the Australian Electrical Safety Standards Mark(s), and in some cases, also look for the Supplier's Number.