[arch-general] lost+found is quite big, although I haven't lost anything?

Hi, since the free space on my system is getting less and less, I was about to clean it up when realizing that my "lost+found" directory on this ext4 formatted partition is about 37G big. The system hasn't crashed so far, wasn't shutdown improperly (as it is attached to a UPS), so its seems quite strange to me. I immediately unmounted the partition and ran an fsck (both with and without the force parameter), but it hasn't reported anything wrong, nor cleaned up the directory. I'm now a little bit concerned as to why this happened and what to do about the directory. Can it be safely removed? Where do this 37G come from? Best regards, Karol Babioch