1995 eldorado: Coolant release last night in driveway after shutting off

Several days ago, my on-board displayed a number "4" and indicated I needed to check my coolant level. Temperature never exceeded normal operating temps (always between 202-223). When cooled down, I did check at the radiator cap, middle way back toward firewall right side near inner fender-well in engine bay. I was low approx. 10-cups of water. Refilled and checked various times during the next 2-days and the level remained constant, again with no higher-than-normal temperatures.

Last night, drove home, again normal temperatures, and backing into the driveway, 216 degrees. My usual route to and from work in Japan, 25 mph, with about 20-traffic signals.

I turned the car off, got out, and then heard what sounded like a pop or cork coming out of a bottle. Then what sounded like water being poured onto the driveway. I moved to the front and underneath saw water draining down, facing the front end, to the right side. There is an open section of the radiator core support and what appears to be frame, about the size of a square drink coaster. Just above that, looking down from the engine bay, a radiator hose. Putting my hand up through the coaster-sized opening I couldn't feel the radiaotor drain plug to see if it had 'given up'. Not sure either if the hose itself was the point of failure. Or, whether the radiator 'gave up'. Would think that operating temperatures would have increased significantly if a closed thermostat was the problem. that did not happen. Anyone seen this before? Any insights or recommendations are welcomed?

:crying2: