So I've encountered links to [this 2023 Meduza publication][1] on Politics.SE, which states:

> In 2022, when the city was the site of a months-long battle between invading Russian forces and the Ukrainian army, 90 percent of Mariupol’s apartment buildings and 60 percent of its houses were destroyed, according to a UN report.

This is mirrored by [another article saying the same (in Russian)][2], to confirm that it is not a fluke but a claim made in earnest:

> Во время боев за Мариуполь в 2022 году было разрушено 90 % многоквартирных домов и 60 % частных домов, сообщали в отчете ООН.

The problem with both of these claims is that they both reference the same [OHCHR report][3], which states that

> We assess that up to 90 per cent of residential buildings have been **damaged or destroyed**, as well as up to 60 percent of private houses.

This report does not contain actual evidence that all 90% of these buildings were actually destroyed, but it does not disprove that claim explicitly either. 

Were 90% of Mariupol's apartment buildings destroyed?

  [1]: https://meduza.io/en/feature/2023/06/30/we-want-to-live-near-the-sea
  [2]: https://paperpaper.io/vojna-zhe-ne-budet-idti-vechno-kto-i-za/
  [3]: https://www.ohchr.org/en/statements/2022/06/high-commissioner-updates-human-rights-council-mariupol-ukraine