Some of my newly rooted cuttings are randomly wilting and dying.  Can't figure it out. 

I don't see fungus gnats, and I boiled the dirt I used for potting to kill any gnats. 

Heating pad is set to 77 degrees.   

I was away about 2 weeks ago and they started to wilt, but watered them and they all came back.   Then a week or so later some are just randomly wilting and dying.  

Is it a delayed reaction to the drought, or something else?

Too much water can be a big problem. uf they were dry then you Water them to much the Bottoms of the Cutting will rot. Lift one up and look for soft wood

That could be it.  I know my little one was watering them when I wasn't there and may have over watered.   

How could I tell?  the roots are still there, although they are turning brown/orange, not longer white.

Pithium or Phytopthera possibly.  I have had issues with what I called "Infant Mortality" in my well rooted fig cuttings, leaves wilt, cutting dies with no other problems shown.  This is something that I have just discovered while trying to figure out problems in my Adenium Obesum (Desert Rose) seedlings.  I don't know if this is the answer or not but I think it is something that deserves further study.

font edits

Fig Legacy: Is it all one variety from one source? If so then it may not be anything you did. They may have some fault and it just happens.

If its several varieties it is likely something you are doing. Sometimes when plants get dehydrated (especially cuttings that are just getting going) we over water them. If their root system is damaged from being dehydrated, heavily watering them is the worst thing you can do since they have no way to dissipate all that water. So they then rot.

I believe that the excess humidity might have something to do with it. I've had this happen
when I used regular cups to root. Recently it has not been a major problem and
when it does happen some cuttings end up recovering.
My theory is that excess humidity could damage the newly formed roots.
Regardless, I believe that "infant mortality" is something that cannot be totally eliminated.

Likely too much water. What kind of planting medium were you using? And did the pots have drainage? Air is just as important as water for the roots. 

I'm using organic soil from Home Depot that I boiled first to kill fungus gnat larva.

I put them in plastic cups with holes drilled in the bottom for drainage, but maybe it's not enough. 

They are all from the same tree.  I'm starting to think it's the drought then too much water + poor soil aeration.  I forgot to put perlite into the soil this time so it's pretty dense. 

You make a good point about "infant mortality" - it's something I thought I could prevent if I did everything right, but guess nothing's perfect. 

Thanks all for the input, looks like I need to watch my watering. 

"Infant Mortality" is not a cause, it is a Time of Death.

I also use the term "Juvenile Mortality" to describe a well rooted young tree, generally 1 gal size that suddenly wilts and dies.  I believe that the symptoms described in Pithium or Phytopthera description may be the same or nearly the same, further study is required.

Hopefully others will do independent study as well and conclusions can be discussed.

Danny: How would you definitively confirm that the cause is actually Pithium or Phytopthera?

@Blackfoot - I am not sure one could determine that "Definitively".  I am just starting the study of this.  One answer to your question could be "How can you definitively determine that it is not?", LOL

I would urge all to spend a little time reading the available information and we can discuss it more thoroughly.  The power of the forum is the "sum of the parts", coalescing the information gathered by many.  When I learn more, I will start a new thread for a discussion so that we don't hijack anyone's thread.

OK Danny. I look forward to the new thread.

Excess water or humidity are likely.  Also, if there has been a sudden change in humidity, moisture or light then that can shock them.  When they get all wilted sometimes you can save them by cutting off the wilted new growth and leaving just one leaf that has been cut in half.  Sometimes, if the bottom of the cutting is rotting, then you can cut off the new growth, cut off the rotted portion until you get to healthy looking tissue, and start the rooting process over again. If I do this, I let the newly are-cut cutting soak in warm water for a few hours before attempting to re-root.  If you are not already, maybe you could try using the 3-cup perlite rooting method, as it is fairly easy to control moisture.

What is the 3 cup perlite method?