While some see a recent string of three battery fires involving Tesla Motors' [NSDQ:TSLA] Model S electric sedan as nothing more than unfortunate happenstance, the National Highway Traffic Safety Administration (NHTSA) is delving deeper into the matter, seeking detailed records from the two fires that occurred in the United States.

On the other side of the Atlantic, Germany's federal transport agency, KBA, has decided the Model S exhibits no manufacturer-related defects.

The NHTSA, in a letter to Tesla (via the Detroit News), is seeking a detailed description of all possible outcomes of a debris strike to the Model S battery pack, plus any limits inherent in the design in regard to fire control and damage tolerance. The NHTSA is also seeking any information on design or material changes planned or already made to prevent further similar fires.

On top of that likely mountain of engineering data, the NHTSA also wants Tesla to turn over records from the vehicles involved in the fires, owner information, and certain internal communications on the matter.

While Tesla's fire-safety future in Europe seems, for the moment, to be bright, it's not yet clear what might come of the deepening NHTSA investigation. The fact that three of the fires have happened to date (though the incident in Mexico was subsequent to a catastrophic crash) has raised some concerns about the car's safety, though many have been quick to point out that cars of any propulsion method do, in fact, catch fire routinely. Tesla CEO Elon Musk, however, is confident the NHTSA will find no fault in the cars.

In fact, the owners of the burned Model Ses have all expressed their appreciation for the battery malfunction warning given by the car, offering them the opportunity to safely stop, exit the car, and get to safety before any fire began. Likewise, all three have expressed their desire to purchase new Model Ses to replace the lost vehicles.