First time contributor to the community, so sorry if this has already been discussed, but I found an easily replicable event inside the first tutorial room—by smacking a gas can hard enough to cause a spark 6 times, and then throwing the weakened gas can directly into the center of the recess that holds a radioactive capsule, the can will explode and leave soot in the shape of a pentagram (at least, I think it is). Kudos to my brother, at his behest, for telling me to use the gas can to try and knock the capsule!

To add on to this, another explosive-related secret (probably a bug) can be seen with explosives and the walls, by picking up the concrete debris that the explosion causes into the inventory and then placing it with any method, it will be on fire for some reason? idk, interesting nontheless. Tested this with other flaming objects, seems to be unique to debris.

I also had that;>