It could be the pan gasket but they arent very common to leak that bad unless the stock molded pan gasket was replaced at some point with a cheap cork or thin black composite rubber gasket and those never seal on these pans because they werent stamped to work well with that type of gasket. A more common area of leak is an axle seal at either end OR the differential housing is damaged and has a crack or hole in it because the differential is failing. The only way to know for sure is to get under the car and clean off everything good with a can of spray parts cleaner or brake cleaner to get everything dry and then let the car sit. It will also help to lay a clean piece of card board under the car to know what area to start hunting
