SAN FRANCISCO (KRON) – A lot of questions still remain – Who are the victims? What caused this boat fire and why did it happen?

The NTSB says no black box was on board because a boat that size is not required to have one.

Now investigators are trying to fill in the missing pieces but this is what we know so far.

Mayday calls after five people escaped the flames and sinking of the conception diving boat off the Channel Islands.

The captain and four crew members were on the upper deck at the time while searchers believe 34 others were sleeping below the deck.

So far, searchers recovered 20 bodies, 11 females and 9 males.

After no new signs of survivors, the Coast Guard transitioned from rescue to recovery mode as other agencies, like the NTSB, dive in to help.

“We’ve begun to obtain factual information and documents. We’ve reached out to develop a list of people we would like to interview and as I’ve said the investigation actually began before we even arrived on scene,” Jennifer Homendy with the NTSB said. 

Investigators will review what happened leading up to the fire, as well as the vessel layout and its operations.

On one recording, you hear a dispatcher asking about locks on the boat.

“Roger, are they locked inside the boat?”

But investigators believe the fire is what trapped the other passengers.

“There are no locked doors in these spaces, the only privacy are curtains,” Captain Monica Rochester, with the U.S. Coast Guard, said.

A former passenger posted a video from a 2018 trip.

Another former passenger who slept on the boat just a month ago says the boat was in great condition.

“It was very well capped. Everything was well maintained. I remember sitting on the deck looking around saying no way that this is the same boat that my dad used to dive off of when he was my age.”

Now more questions than answers remain from Monday’s trip on the conception.

“I am 100% confident that our investigators will determine cause of this fire, why it occurred, how it occurred and what is needed to prevent it from happening again.”

The NTSB says they’ll remain on scene for seven to ten days as they continue their investigation.

They say the final report could take one to two years but expect to have a preliminary report ready in 10 days.