I believe that they have been told by authorities to remain silent in public till the investigation is complete.
Correct.
I actually have some first hand experience with such things so I might as well entertain you all with a break down of what happens directly after an accident.
1) The first thing that happens is that it is treated as a crime scene. All the gear is seized, the victim's body is recovered and evidence is collected. This is logical because for obvious reasons police can't just take everyone's word for it that it was an accident.
2) in this phase the survivors are usually offered psychological help (where I live). At the same time they and all other witnesses are questioned by police and a dossier is built up with all accounts of what might have happened. During questioning the survivors may consult or be assigned a lawyer. These lawyers *always* tell them to keep their mouths firmly shut until the police investigation is finished.
3) The coroner's account is a key piece of evidence for the police so no decision about whether or not a crime has been committed will be taken without that input. The coroner usually does their job within a few days.
4) at some point the police will decide whether or not a crime has been committed. If the determination is taht it was an accident (as will be the conclusion in this case) then the survivor are "off the hook" and able to talk. We're not there yet.
5) the rest of what happens after that depends on whether or not there is a legal follow up, which there usually is. that could be criminal or civil case or between the victim's family and insurance agencies or whatever. This is the part that usually ends up being messy.
R..