The exact same thing happened to me in my old mindcrack world. I had around 16 cobble generators along with 16 igneous extruders feeding cobble into some recyclers all going into a mass fab. One day I logged on and I started hearing random explosions. I thought maybe it was a pipe or something but it wasn't. The sound did indeed get louder as I approached the mass fab and the recyclers but I never found out the source of the explosion sounds. About 2 weeks later, I updated my modpack version and my stupid world save got corrupted. Man I was so f****** mad that I didn't go back to playing until 3 weeks or so. I had 8 FUSION REACTORS in my world which I just got. Not to mention a 3gb save.
Edit: 100th post FTW
Edit: 100th post FTW