Should parents who go about losing small children on a regular basis be investigated?

I wouldn’t put it to the level of losing small children on a regular basis. They have ahd one targedy, and perhaps one more in their lives.

They didn’t lose the two year old, he walked on a poorly covered borehole.

Nah.
I lose, and misplace things constantly.
Nothing that amazon can not solve.

I’m not sure what happened to the previous child, but this article states they were standing around and they watched him fall in, which I wouldn’t call neglect if they didn’t realize it was there.
(Disclaimer: I am not a parent and have been told I am not qualified to answer any parenting questions.)

Someone knew it was there because it was covered loosely with rocks. I’ve witnessed people personally who some how don’t think their child will not get into that kind of trouble. We were camping once, and some camping neighbors were visiting. They had their grandkids with them. One of the kids was less than 2. It was dark, and I suggested we lock to door to the camper so the kid wouldn’t open it and fall out. .
She said, “Why would he even want to go out there? It’s dark out there!”
I was left opened mouthed in astonishment. She was a grandmother. She has had experience with kids.
I just shook my head like, OK. I guess it’s not my job, not my business.
Well, not 15 minutes later someone came in. They shut the door behind them. The toddler went right to the door and opened and started to step out into the pitch blackness.

Why? How many have you lost??

To lose @ragingloli once would be regarded as a misfortune; to lose @ragingloli twice would smack of carelessness.