Hi bbowling you might be able to achieve this with a couple methods. Method 1 is kind of crude but effective you simply make a sprite that is invisible and if player is overlapping this sprite cause death events then just place the invisible object where you want. Method 2 is using the platformer "is falling" and a system wait X seconds like the image below. Hope this helps.
If you're looking to make fall damage use a global variable that kicks in and then if on landed and variable=1 do the death or health loss events. Kinda like this.
You can also make it so it waits for a second then starts increasing the global variable and you can take fall damage based on how far you fell. If you need an example of that I can provide 1 just let me know.