Hurricane Sandy might be the cause for those 16 Karma and 3 Prius hybrids burned at New Jersey port.
Toyota spokesman Cindy Knight said the cause of the fire was because “saltwater got into the electrical system”. Taking into account that saltwater is highly conductive, when it gets in contact with an EV’s battery it could result in a short circuit and a fire. She added that a plug-in hybrid Prius completely burned, while another plug-in and a regular Prius got really hot and smoldered.
In an official statement, Fisker said a low voltage Vehicle Control Unit in one of the cars is to blame for the fire as it was under salt water for a few hours and then short-circuited. Fisker also mentioned that the lithium-ion batteries inside the Karmas were “ruled out as a cause or contributing factor”.
Daniel Abraham who is a chemical scientist working at Argonne National Laboratory explains that salts in water break into positive and negative ions that act as conductors which might have connected the positive and negative terminals of the batteries, leading to a short circuit and then a fire.
In the press release section you can read Fisker's statement.