UPDATE Oct. 4:

Elizabeth Jarvis-Shean, Tesla's director of global communications, wrote in an email to the media on Friday afternoon:
"Today, Tesla posted this blog about the Model S fire near Seattle, WA this week to our site: http://www.teslamotors.com/blog/model-s-fire."

Excerpt of statement from CEO Elon Musk:

"When the fire department arrived, they observed standard procedure, which was to gain access to the source of the fire by puncturing holes in the top of the battery's protective metal plate and applying water. For the Model S lithium-ion battery, it was correct to apply water (vs. dry chemical extinguisher), but not to puncture the metal firewall, as the newly created holes allowed the flames to then vent upwards into the front trunk section of the Model S. Nonetheless, a combination of water followed by dry chemical extinguisher quickly brought the fire to an end."

Meanwhile, the company's stock down 6.2 percent from Wednesday, the first full trading day after the Model S fire incident in Kent, Washington, to $183.46 in Friday after-hours trading.

Original story begins here:

Tesla Motors Inc. (NASDAQ:TSLA) has lost about $2.5 billion in value since markets closed on Tuesday, the same day a black Model S electric sedan struck a metallic object on a highway south of Seattle and erupted into flames that responders said got worse when, according to an incident report obtained by International Business Times, they sprayed water on the vehicle to extinguish them.

On Thursday afternoon, the stock was trading around $173 a share after closing on Tuesday at $193. Co-founder and CEO Elon Musk, who owns about 23 percent of the company, is a little less of a billionaire on Friday since the value of his stake has shrunk by about $594 million.

Meanwhile, Deutsche Bank Securities Inc. issued a research note that appears to have been written before news of exactly what the firefighters of the Regional Fire Authority of Kent, Wash., 20 miles south of downtown Seattle, confronted. “The fire dep’t was called, arrived at the scene and extinguished the fire without further incident,” wrote Deutsche Bank analyst Dan Galves in a note that rates TSLA a buy.

As Deutche Bank pointed out, the Model S has driven 83 million miles and has had only a dozen significant accidents; this is the first fire in a Tesla vehicle. But how the fire team extinguished the fire on Tuesday should not be considered “without further incident.”

“The fire appeared to be extinguished, then reignited underneath the vehicle,” said the incident report. After they sprayed the car with water, the situation got worse. “The application of water seemed to intensify the fire activity.”

Responders then applied dry chemical flame retardant, which “put down the majority of the fire.” But in order to fully extinguish the flames, responders had to use a circular saw to “cut an access hole into [the] front structural member to water the battery pack.”

The incident underscores an important question about electric vehicles in general – and especially electric luxury vehicles that are more likely than smaller, dinkier EVs to be speeding down highways: How should firefighters respond to EV fires? What happens if there isn’t a driver alive to inform them that the car is electric? Do firefighters need to be aware of EV models so they know automatically to apply dry chemical flame retardant? Will they need to cut EVs open to fully extinguish the flames?

There are all significant questions. Hopefully the National Highway Transportation Safety Administration, currently shut down due to congressional incompetence, will open up again soon to look into the matter.