A little more information (as i was one of said people being killed). While yes there may be issues of cooling them the pump was green, but yes that could have been a bug. It was my understanding however that it would explode, whereas this was a continuous pulse of damaging... something or other for the entirety of the 25-35 minutes. Any items thrown into the area would be destroyed when contacting the area as well. There were only 3 players on at the time and the other was far away from us the entire time so I had doubted that could be it.
If combustion engines can do that for 30 minutes (in what seemed to be a sphere of sorts with a diameter of 9 blocks), then I shall hang my head in shame at my lack of understanding. I would appreciate any insight into the matter however.