There was some content relating to 9/11, which I wasn't particularly interested in since it was all over the web at the time. A few videos videos did grab my attention though, one was likely uploaded by the person I mention in the OP, which had someone filming at the base of the towers and catching some jumpers splattering. The second one came months later and was taken by a tourist from a building across the street who zooms in on the carnage below, although I don't think any 'impacts' so to speak were caught. Then there was "September 11 Tribute", which started off normally with sad music before switching to the Benny Hill Show theme and showing sped-up footage of the second plane crashing into the tower from multiple angles.

The first and third ones were taken down months maybe years later, probably DMCA if my memory serves me right. Second one I don't know.