Coolant filled oil pan

I would like to add that the truck has been sitting, and not running. When I put the coolant in the reservoir it immediately went through and out the oil pan. Immediately, like no resistance with the truck off and not even warm. Would this indicate a head gasket? Or cracked block? Could it possibly be a leaky gasket at the water pump? Up until I parked it a year ago. It was running without overheating or white smoke. It hasn't even been started in over a year. For it to go directly to the engine literally as I poured the coolant in.