A new bug was discovered in Fortnite Battle Royale, check it out, the bug will be fixed quickly!
It seems that a bug allows traps to work through walls in Fortnite. A video posted by Reddit user mynameisdiehard is quite convincing, and several other users in the thread also confirm it.
Fortnite – Fallen Bug / Exploit
Trap bug CONFIRMED!!! Damage applying on opposite side of wall! Traps need removed or fixed ASAP! from r/FortNiteBR