Ok, this is what I know.
Apparently, the gun was brought back to armskote without proper
clearing. No one was aware that a round was still present in the
chamber. Worse thing is DO never check clear all arms when T/O. So
you can guess how many ppl down the line are gonna get it.
While attempting to remedy the gun, still unaware the round was
present. The bolt was pulled and the firing pin triggered the round
causing it to go off. Yes, in the armskote. Imagine how loud thats
gonna be. Good thing the open chamber was facing the ground. So now
got ppl partially deaf and blind. Very unlucky.