The sinking of a large cargo ship carrying thousands of luxury cars has sparked renewed concerns over shipboard safety and may prompt insurers to raise marine rates.

With nearly 4,000 automobiles on board, the Felicity Ace caught fire 90 miles off the Azores on Feb. 16 and sank on March 1. The 60,000 ton vessel's cargo included pricey Volkswagens, Audis, Porsches, Lamborghinis and Bentleys, as well as a number of fully electric vehicles.

The fire itself onboard the Panamanian-flagged ship, insured by Britannia Steam Ship Insurance Association Ltd., would have generated economic losses totaling $155 million, risk solutions company Russell Group reported in an analysis. The value of all goods onboard totaled $438 million, of which $401 million are for the vehicles, the analysis also estimated.

Volkswagen Insurance Co. DAC, the captive insurer for Porsche Automobil Holding SE, insured the cargo, said Rob Hawes, head of global marine at Crawford & Co.

The sinking of the Felicity Ace was a "unique event" considering the high value of the cargo, and could have a broader effect on the market, said Ronnie Adcock, a Sedgwick senior vice president responsible for marine claims in the U.S.

"I'm sure it's going to have an impact, that people will want to talk about and try to use that to increase rates," Adcock said in an interview. "You're seeing more and more marine casualties around the world with cargo containers going overboard."

Hawes said the destruction of the electric cars will exacerbate the loss totals for Volkswagen, which he estimates is between €150 million and €200 million, or $165 million to $220 million. That is a heavier loss than the $30 million to $50 million he estimated for the loss of the container ship Xpress Pearl, which caught fire off Sri Lanka on May 21 and burned for 13 days.

Determining the cause of the fire that led to Felicity Ace's sinking will be almost impossible since it went down in rough seas that were nearly 10,000 feet deep. The ship had stability issues as it was being towed to the U.S. due to a significant starboard list caused by the amount of seawater pumped into the ship to extinguish the fire.

Much of the speculation about the cause of the blaze has centered around the lithium-ion batteries used in electric vehicles. Fueling that speculation is the batteries' reputation of volatility and their propensity to catch fire.

Lithium batteries are "creeping up the list" as a cause for container ship fires, according to the research of Martin Hall, head of marine casualty for the law firm of Clyde & Co. He said those fires have become a major problem for car carriers because they are transporting electric cars more frequently.

"If the reports are accurate that the fire started in the car deck, then that would tend to suggest it may well be a vehicle that has caused it," Hall said in an interview. "It brings into focus the lithium batteries, and it's clearly something that I would expect the insurance industry will be concerned about."

There is insufficient regulation or procedures in place for electric cars, which "obviously cause [a] higher risk of fires and [are] less known to the crew," according to Lars Lange, secretary-general of trade body the International Union of Marine Insurance.

A number of proposals are being considered for the safe transport of electric vehicles, such as not charging batteries on board, improving crew monitoring of the car decks and enhanced fire, smoke and heat detection, Lange said in an interview. Those issues will be addressed by the International Maritime Organization, he said.