Reasons for deformities

This is the first Leo egg that was going great then stopped growing and died (it's clutch mate hatched almost 3 weeks ago) I opened the egg and the babies tail was short (barely a third of a normal tail) the body had very weird patterning to it and the head was misshapen and small. I will add, around 4-5 weeks ago our breaker disconnected and the plugs for my incubators stopped working for a while (it was overnight) I did a very gradual raise back and had 16 bearded dragons hatch and a baby Leo. I believe I lost another egg to either mold the power incident or both, but the other 6 in there when the power problem happened are still growing. The parents have 5 healthy hatchlings and are first timers. Thank you!

There are a number of reasons why deformities may occur (I assume this is what you're asking):
--genetic abnormalities
--luck of the draw --mutation
--temperature fluctuations in the incubator (this is my second season with a new, much improved incubator and so far I've had ZERO abnormalities, compared to about 10% in previous years.)

Aliza