I had the same thing...
Set six eggs
All veined
2 quit fairly early (blood ring)
2 cracked
1 quite after week 3
and I have one left due to hatch next week
For me, it was a homemade incubator with some wacky temp swings. The darn thing was just too small. Also my son unplugged it at one point. I had to rebuild it after a light socket cracked too.
If this duckling actually hatches, I might have to name it Murphy!