When going into a nether portal from the Overworld which leads directly over a lava ocean/lake, the portal is destroyed as soon as it is created upon the user entering the nether, therefore, allowing for the user to fall into the body of lava.

When I created the portal in the overworld, I was certain that I was not in range of any portals to accidentally link to. With this in mind, I was going to generate a new portal in the nether which happened to be located above a lava ocean. Upon entering the newly created portal, I spawned inside the portal frame only to hear the shattering and breaking of the portal to which I began falling into the lava lake below where I spawned into the nether.