1995 Park Ave Won't start

[park95ave]

I have a 1995 Park Ave. Got in the car tonight, it started, while backing up it died. Tried to restart with no success. I then tried to jump start it using jumper cables, still will not start. I don't know if the battery is dead. The radio or lights don't come one either with the jumper cables connected. I also tried to use battery pack which was fully charged to start it but still no success. What is strange is that no lights on the dash or external lights or radio works when the jumper cables are attached neither with the battery itself. Can you please help me.

thanks.