There are better sources, but here's a good start. CBS:

There Was No "Tiananmen Square Massacre"

https://archive.is/Gqz1A

Peculiar you don't quote this:

But there's no question many people were killed by the army that night around Tiananmen Square, and on the way to it — mostly in the western part of Beijing. Maybe, for some, comfort can be taken in the fact that the government denies that, too.

But maybe it really makes it "the night when nothing at all happened" for you, a literal tankie.