My fire alarm is going off. I know lots of them do that on low battery, but this is reaallly going off. I can't turn it off either. Does anyone know what this is??? It's driving me insane. I need to gosomewhere but I don't want to leave, in case there is actually a fire. Has this happened to anyone before?

I have checked for fires around the house. Nothing. It does seem kind of hazy, though...