I started typing, but it is honestly too complex to summarize without severly distorting the story. There were radical student leaders who pushed things to a very dangerous level, there were protestors who just wanted to party, there was police on the side of the protesters, and high party members, and counter-protesters. There were military people who just wanted to slaughter people, and the government, in the end, was taken over by the hardliners in support of the military leaders wanting to crush dissent.

I think the crux in understanding chinese peoples attitudes on the issue today is this: Yeah, it might be a tragedy, but today everyone is far better off than back then, and everyone is glad they didn't go the way of the USSR.

The first article I posted gets into a bit of detail about the CPC internal power struggle, basically the moderates and good guys were all purged in the aftermath of the 1989 protests.

The documentary is probably the most important media I would anyone implore to watch if they want to understand China. It goes into such incredible detail from an outsiders point of view without ever disregarding China's own perception, it is truly a masterpiece.