DETROIT – A Tesla Model S electric car caught fire this week after hitting road debris on a Tennessee freeway, the third fire in a Model S in the past five weeks.
The blaze on Wednesday afternoon near Smyrna, Tenn., engulfed the front of the car. A spokeswoman for the Tennessee Highway Patrol says the Model S ran over a tow hitch, which hit the undercarriage of the car, causing an electrical fire.
It’s the second Model S blaze involving road debris.
Shares of the carmaker, based in Palo Alto, Calif., fell 7.5 percent to $139.77 on Thursday. That’s on top of Wednesday’s plunge of 14.5 percent. The shares are still up 312 percent this year.
The Model S has as a large battery pack under the passenger compartment, protected by a quarter-inch-thick metal shield. Experts say that if debris punctures the shield and damages the battery, it can cause shorts and arcing that can touch off fires.
The National Highway Traffic Safety Administration, the U.S. government’s auto safety watchdog, says the agency will contact Tennessee authorities to determine if there are safety problems that need further action.