From Wikipedia:
The April 9 tragedy refers to the events in Tbilisi, on April 9, 1989, when an anti-Soviet (but pro-Stalin) demonstration was dispersed by the Soviet Army, resulting in 21 deaths and hundreds of injuries.
I find the pro Stalin comment interesting.
Here's a memorial although there seem to be too many names.
It's here (click this link)
And this lady is also in the park, I don't know who she is, but some monkey has enhanced her pubic region with a black felt tip pen.