Another Tesla Model S has caught fire in Tennessee after reportedly hitting a piece of debris in the road. This marks the third Model S fire in the past six weeks, and could cause the National Highway Traffic Safety Administration to start an investigation.

The blaze reportedly took place near Smyrna, Tennessee on Wednesday after the driver ran over a trailer tow hitch, with a photo of the burnt Model S appearing on the Tesla Motors Club forum.

In a statement released by Tesla, the automaker said, "We have been in contact with the driver, who was not injured and believes the car saved his life. Our team is on its way to Tennessee to learn more about what happened in the accident."

The first fire happened early last month in Kent, Washington, when a driver ran over a large metal object, puncturing the armored plate that covers the battery pack underneath the vehicle.

After that initial incident, the NHTSA released a statement saying that, "After reviewing all available data, the NHTSA has not found evidence at this time that would indicate the recent battery fire involving a Tesla Model S was the result of a vehicle safety defect or non-compliance with federal safety standards."

The second fire took place last month in Mexico when the driver lost control, went through a wall and into an embankment, and then struck a tree. Video of that fire surfaced online, but because the NHTSA has no jurisdiction in Mexico, there was no federal involvement.

This third fire may be different.

While there are an average of 150,000 car fires in the U.S. each year, with only 19,000 Model S sedans on the road, having three vehicles catch fire in six weeks has garnered plenty of attention.

Punctuating that point is the fact that neither the Nissan Leaf EV (approximately 70,000 sold) or the Chevrolet Volt gas-electric hybrid (around 50,000 sold) have suffered similar fires.

Yahoo Autos spoke with Nissan spokesman Brian Brockman, who confirmed that "there have been no fires involving the Nissan LEAF, either through extensive and extreme testing or in the real world." General Motors spokeswoman Michelle Malcho echoed a similar sentiment, saying that "to GM's knowledge the Volt has not experienced a fire on the road."

While all three vehicles use the same lithium-ion battery chemistry, the Model S has four times more energy stored onboard and spans the underbody of the vehicle, unlike the Volt which employs a T-shaped battery pack and the Leaf which uses a pack placed towards the rear of the vehicle, where the fuel tank would normally reside.

The Model S was recently awarded five stars from NHTSA for safety – the highest possible score – and after the first fire Tesla CEO and co-founder Elon Musk defended the Model S's safety, saying, "For consumers concerned about fire risk, there should be absolutely zero doubt that it is safer to power a car with a battery" than a conventional gasoline-powered vehicle.

According to a statement from the NHTSA regarding the fire in Tennessee, the agency "will contact the local authorities who are looking into the incident to determine if there are vehicle safety implications that merit agency action."

CORRECTION 11/7/13 6:39 PM ET: An earlier version of this story misstated the statistics of car fires related to the number of Model S sedans on the road.