Check if there are any lights around. If there are, observe the surroundings.
> Look for any derranged killers, death traps, small children or bones.
Attempt to grab the bone and break your chains off.
How does decaying brittle ribcage manage to break a metal chainif the chain was weak enough to break using a ribcage, then it was weak enough that you could just snap it off by pulling.
(He was fiddling with the lock hole my good sir.)
I'd just lop off the chains and go Hammerfight on the monster's ass