I believe the children were alive - the shadows by the truck tell that story pretty clearly to me. What I don't believe is that that 45 minute ride was quiet. I think the girls were horrified and crying/screaming/climbing around all leading up to him easily murdering them the moment they got there.
The girls were dead before CW ever left the house! It’ very important to not be influenced by what CW has said, but instead to look at things clearly and logically. The only reason to take Cecelia and Bella our to the jobsite alive would be; he initially didn’t plan to kill them, but that makes no sense at all.
1. CW is a proven liar, he’s lied about everything! Any truth he might speak benefits him and/or is meant to influence others to benefit himself. His truths are not absolute, but are very malleable, as it suits him.
2. If he kept them alive all the way out to the jobbsite, it was with their mother’s lifeless body, and one, or both of them, would have been hysterical!
3. Once they knew their Mother was dead, CW had no way to hide or manage Shanann’s murder. Eventually Cece and Bella would have told the police or family, and even (not very bright) CW would know that. Keeping them alive would have been a huge risk!
4. If CW planned to kill his daughters, why would he risk a 45+ minute ride with hysterical children and risk one of them trying to run from him at some point?
5. His scenario makes no sense! Why would he kill the quiet, docile child first, leaving the aggressive, older child unattended? What if Bella had gotten scared and run off while he was up on top of the tank? Children, particularly very young children, are unpredictable. As afraid as she may have been of him, being alone with her Mother’s unresponsive body would have had a major effect! How logical is it that CW would have left Bella, or either of them, unattended?
6. Nobody saw or heard Cece or Bella after they face-timed with their Grandfather! There is no video or evidence showing CW carrying or leading his daughters to the truck. Given all of the video footage we have seen, how likely is it that one or both of the girls would not be seen? For instance, Bella seems the type that would run after her mother, crying and maybe screaming, as Shanann is carried to the truck! Shadows prove nothing and the video shows only bundles being loaded into the truck. CW’s reactions later, when he was shown his neighbor’s video, proves he was unaware of the video, so he wouldn’t have been overly cautious about his daughters being seen, if they were alive! But, they weren’t seen!
All the facts and evidence show that CW was madly in love and fixated with NK. In his own words; he had never met anyone like her. In his own words he wanted a fresh start with NK! A logical evaluation of the facts and evidence leads to the conclusion that CW wanted to be free, in all ways, from his family. The logical conclusion is; he wanted them dead! The fact that they are ALL dead supports that conclusion. So, he wanted them dead, and that shoots down his declaration that killing the girls was a last minute decision. The logical conclusion, based on facts and evidence, is that he killed the girls as soon as possible and killed Shanann as soon as she arrived home. Why have an “emotional discussion” with someone you plan to kill, unless it’s designed to hurt or torture them? What could he do or say to hurt or torture Shanann? She suspected and probably knew he was having an affair, so how hurtful or tortuous would confirmation be? Not very. How about (his words); “you’ll never see your children again”? Attributed to him, not her, because they were dead!