I have a Kenmore Coldspot 106.54596400 fridge that's more than 10 years old. It's a side-by-side. Today I noticed water leaking from the bottom of the freezer through the door and the discovered a large puddle and pieces of ice on the bottom. Is this a sign of some type of drain being plugged? Googled it but could not figure that out. If there is a drain hole somewhere, where is it? If it's not that, what can it be? Thx much!