https://www.liberationnews.org/tiananmen-the-massacre-that-wasnt-2/

Edit: the other source I was looking for

https://archives.cjr.org/behind_the_news/the_myth_of_tiananmen.php

The thing to get is that there was no massacre on the square, and in fact there's no verifiable evidence that anybody died there at all that day. Many people did die elsewhere, in street clashes with soldiers, after demonstrators killed and burned a few of them.

I would like to note also that bringing up events like Tiananmen Square, especially heavily propagandized and warped versions of them, without an understanding of the complex political context which led up to them, is not a gotcha, it's just ignorant. Not saying you're doing that or that you would do that, but it's something others do frequently when they invoke it round here.