Took a closer look at that burnt wool that was near the fire. Couldn't make out much about it... looks like it might have been a piece of clothing, off-white in colour, but it doesn't have a distinct shape now.

Didn't look like it was bunched up and burnt on purpose [as another culprit seemed to do in a previous case] so... I don't know. Maybe it caught fire while someone was wearing it, and they discarded it on the spot.

There wasn't any other damage or stains on it, besides the burnt parts.