That would somewhat depend on the circumstances. But, it would be appropriate to inform someone of a supervisory level position that would be responsible for ensuring that no one was injured because of it. In some places they'll deal with it in an immediate manner, and in other places they may be aware of it, and hoping no one gets hurt or realizes it. If they don't deal with it, they are infringing upon your right to a safe work environment. It would probably be best if you let someone know about the situation.