[JayGalt]

https://nypost.com/2018/03/29/moms-of-family-who-drove-off-cliff-have-dark-history-of-abuse/

Link with reference to the abuse I noted above. There are other stories that appear to be different neighbors with similar stories.

In this article:
“Officials say they tried unsuccessfully to reach the family three times to investigate — but the neighbors say the family fled when a CPS worker showed up at their door Friday.”

“The next morning when we saw that the vehicle was gone, and then Sunday morning when it still wasn’t there, we figured something was off,” Bruce DeKalb told local NBC affiliate KGW.”

That was immediately before the car went off the cliff.

[JayGalt]

http://www.koin.com/news/washington/friends-neighbors-paint-uneven-picture-of-the-harts/1086124457

More interviews with the neighbors.

[HotHunt]

My take is that this was either one of the women deciding to commit suicide or both and take the family with them.

Sounds like they knew the jig was up and they were about to be caught and exposed as more than "loving lesbian parents".