There's been a few threads talking about vacancies, recession, O&G layoffs, businesses, etc. in the past.
I thought this was really cool, you can see all the available vacancies in downtown and also compare it with the past:
https://www.cubecities.com/altus/pro...ltus/?cityId=2
2014
2018
http://www.cbc.ca/news/canada/calgar...ings-1.4572486