Corrupted realm

I have been playing on my friend's realm, Wheatfields (owned by wheatyface). I was in the realm today a few hours ago and then just came back. When I logged back in, I was suffocating at my previous location (1 or two blocks from -42, 61, 871), which had been a building inside my base. After mining for some air, I noticed the biome was wrong - Ice Plains instead of Desert. After digging myself out, I found that my base was gone - almost entirely replaced by newly a newly generated Ice Plains biome. I checked around and found that the southeast corner of the corruption appears to be 0, -512, and it extends an unknown distance to the north (at least 1k blocks) and west.