suddenly no service?

No service here as well. Gatineau.

Same here, no service in Pointe-Claire, Montreal or Laval it appears.

It is working for me and my family

Same here in Ottawa

Too bad this happened on a Friday night. Another one In Ottawa without service.

Fizz office - no service as well.

@Aleksey P. What do you mean by Fizz office? Do you work for Fizz?

When you say "no service" are you unable to connect to the cell towers or do you have signal and just not able to call/text/use data?

Nothing from the cell towers. Zero bars. Unable to register Fizz network.

no service here in Blainville

Same, Brossard

my friend has no service, Pie IX boul. Montreal

The @Whizz just made an announcement letting us know that there were aware of the issue and are working on it to fix it: https://community.fizz.ca/questions/1825566-re-currently-experiencing-network-issues

@Emre Y. What is your location? Can you make phone call/text? I have zero bar.

@Song J. Currently I am in the Laurentides (North of Montreal) everything is working fine.

--Update-- Data just stopped working I can still Call and Text

No data, no calls and no text here in Ottawa. Can't connect to any networks on Android.

It should be back up. If not:
Besides https://fizz.ca/en/contact-us , there are:
contactform@support.fizz.ca
Facebook Messenger
https://www.messenger.com/t/fizzca
https://www.facebook.com/fizzca/
Contact form
My profile--->Contact forms--->Submit a complaint