I heard about this on Capital FM this morning who said it was a broken down tram. I live in The Pinnacles student accommodation which is right next to Park Square and walked passed the incident on the way into Uni this morning. There must have been around four or five Supertram vans and loads of workmen around, and the area was taped off. I managed to take a few quick photographs as I passed.
Typically, I have to go to the Olive Grove campus of Sheffield College on Fridays for Electrical and Electronic labs (I'm doing the Engineering Foundation year and Sheffield Hallam University have a contract with the college for the Electrical and Electronic module) and I walk along the path that runs next to the tram line. It can get quite busy at 8:45 at Sheffield station tram stop on any morning, but there were loads of people walking down the path heading towards Ponds Forge and the City centre this morning. I saw the first lot near the entrance to Park Hill and realised they had left a tram that had terminated at the station, but a second tram that terminated just before I got the station tram stop made it incredibly difficult to get through everyone!