ive always had this lingering idea that chris was planning to put shannan in one tank and the girls in the other.
that's why he took the gasoline.....
then he was gunna blow up the site like he had some sort of epic accident working there.
(don't know how he would have explained him being far enough from it as it exploded to not harm him...but hey dealing with someone killing their family and doing this in the first place....

)
shanann being pregnant, I believe had had a big bubby growth spurt that last few weeks and she was much bigger than chris fantastically remembered.
she wouldn't fit in the hole.
he had to improvise and shallow bury her. (I think he was always going back to put her in the tank and then follow through with explosion imo)
the big plan (explosion) ...was stuck in a holding pattern for a few weeks.
except for NUA bless her beautiful loving impatience to find her friend xx
**all speculative of course ….but that's where I am at.
moo