Get the appropriate treatment and speak with local/qualified counsel.

Absent a court order, for example; no.

Possibly. Best to speak with IA counsel.

If my husband got rear-ended on the freeway and hit the person in front of him is he at fault?

The car that begins the "chain" is presumed to be at fault; usually.

What grounds do they have to open a investigation ?

How sad and how unfortuante. Lets hope the child is fine.

Most of the time less then with a good lawyer. This is based upon insurance companies own studies.

Can I be held liable for tapping my brake light (not braking) in a rear end collision

Yes, you can; although you havent been, at least not yet.

Hit by a Construction Company Truck, Driver wasn't on their insurance policy... who is responsible?

Always speak with an attorney before speaking with any insurance company. Good luck.

How do i find out who my moms lawyer was she has passed and i dont know who was the lawyer or whats goin on with her case?

Suggest you,start with the county clerk where she resided.

What can I do when a ongoing investigation with two vehicles happened on the other side of the road my car was damaged by debris

If the other insurance companies won't pay, you will need to file suit. Best to use your collision coverage; usually.