Every once in awhile my fridge will leak water from somewhere underneath. I took off the horizontal grill along the base of the fridge and looked underneath to find a white, plastic tray of some kind (see photo below). My fridge has an in-door (not indoor) ice & water dispenser, so maybe this is what the tray is for. I believe the tray is broken and doesn't lie perfectly horizontal, which may be why water is overflowing and spilling out the bottom.
This tray that you speak of is there to collect water made when the frig goes into defrost. The tray is supposed to be large enough to collect all of the water without overflowing. The water is supposed to evaporate faster than it is generated. If the tray is cracked, that is a problem. If the tray does not lay flat, also a problem. If your local atmospheric humidity is particularly high and with the tray tipped as it is, problem. The water needs to evaporate faster than it is replenished and spills over the lowest point of the tray edge.