Server Out of Use?

So I was just on the server earlier with my friend Neon and we noticed that no one had been on for a while. We take a look at spawn and it's COVERED in lava. A lot of it seems like it can't be repaired. Neon is currently trying to get rid of as much of it as possible. We have some ideas as to who might have done this. If this no surprise to anyone let me know. Here are some pictures.