My warning sign was the day before, got a twinge when I bumped open a gate with my belly.
That pumped a gallstone out of my gallbladder where it lodged in the duct and the swelling choked of my pancreatic duct, blowing up my pancreas like a balloon until it exploded.
Which, by the way, is a LOT more painful than it sounds.
Did you never have unusually strong feelings of nausea after a heavy meal or any of the other classic symptoms before that one stone episode?