my kids back to Provo after a weekend in Oceanside CA.

I can tell you that that the fog was so thick coming off of I-5 south of LA onto the beach town toll roads that cars were only driving 35 in a 65.. and I mean every car.

It was nuts...

The information that has come out that the pilot was authorized for visible flight in those conditions.. and the conditions were nasty. As stated above spatial disorientation is a real phenomenon and can be particularly powerful in a helicopter which depends on centrifugal force. This is why pilots are trained/drilled on using instruments and trusting instruments more than their own sensations/senses... terrible tragedy.

It was a terrible lapse in judgement to elect to fly in those conditions IMO