Among other definitions of closure, WordHippo provides the following one:
The collapse of a business. Ex: We have received a very apologetic letter about the closure of the West End Club, but it really left us in the lurch.
Note, however, that "closure" can refer to a temporary state of being closed:
The Mercer Gallery reopened at the weekend after a month-long closure
for maintenance and improvements to the lighting system.
(example found on the same site of WordHippo)
As for closing, you will find such definitions as:
The final stage of an extended process or course of events
Or
The act of something that stops
There is however one definition connected to the idea of bankruptcy:
The condition or state of selling the assets of a business, especially due to bankruptcy
And here you can find synonyms as liquidation, shutting down.
At the end of this little "investigation", I would thing that you can say either
The closure/closing (I would add here of the business) took place at the end of last year.
but you will be surprised to find that Gngram gives definite preference to the closing took place.
To avoid ambiguity though, I would simply say:
The business was closed down at the end of last year.
Oxford Languages defines the verb to close down as:
- cease business or operation, especially permanently.
The company closed down some years later.
- cause a company or business to cease operation, especially permanently.
The government promised to close down the nuclear plants
within twenty years"