If smoke and fire detection systems worked, even sleepy crew should have responded to a fire. Granted if anyone was standing watch they would have seen it when it was possibly easier to fight.
So I would say (1) defective smoke detectors (2) defective crew discipline and adherence to regulations, and (3) a defective charger that provided the spark, and possibly a source of fuel near the charging system? Usually for this level of consequence at least three failures of systems are necessary, it seems that was the case here.
Therefore, this accident was avoidable by breaking any one of the risk factors.
Supposedly had A SMOKE DETECTOR LIKE YOU USE AT HOME. Since the boat was older, wasn’t few to have more modern safety requirements. Maybe like sprinklers.
Supposedly they all died from smoke inhalation.
Many (most?) accidents are caused by cascading failures. One of the reasons why “near misses” are reported in most industries.
Most of the backup systems work most of the time. I wonder how many times on a ship (or at home) the smoke alarm sounds off on a smoldering power strip and the owner awakens and disconnects it or whatever?
But the smoke alarm doesn't sound. Or it does, but the fire extinguisher fails, etc.
One time our dishwasher overheated. It wasn't smoking enough that the alarm in the hallway sounded - but our infant daughter was crying. Nothing we did (feeding, checking her diaper, etc.) would calm her down. She ALWAYS calmed down with that stuff. After 10 minutes in the bedroom dealing with that stuff she was still crying.
So I walked her up and down the hallway. That still didn't calm her down.
I walked through the kitchen and smelled an odd plastic smell by the dishwasher. I went back into the bedroom to give my crying daughter to my wife. I went back to the kitchen and cracked open the dishwasher. The heating element was red hot and the plastic was melting.
I ran downstairs and hit the breaker for it.
By the time I got back upstairs, my daughter was sound asleep!
Smoke alarms and fire extinguishers are great to have. So are guardian angels!