I've been sitting on this news for two days! I heard the stories and then received an email from the operator (as did all agents of the fleet so that we could contact our customers with bookings on the vessel before the news was made public).
There is an ongoing investigation, but it is suspected that the fire started at the location of a clothes dryer on board; the crew were unable to extinguish it, and the fire spread throughout the boat. The divers were in the water at the time, so abandoning the boat and deploying life rafts was made somewhat simpler, though of course passengers' personal effects were lost with the vessel.
As AlMitch said, the Indo Siren went immediately to pick up the divers and the crew. And then a speedboat joined up with them to transfer the divers to Sorong, where they were provided with clothing and a place to stay until they could be transferred to Jakarta. Once in the capital, they were able to get emergency travel documents from their respective missions and procede homeward.
It's a terrible blow, but at least there was only loss of material goods and there were no injuries.