According to Tesla CEO Elon Musk, the California-based automaker requested that the government safety agency open the investigation, saying in a blog post, "We have requested that the National Highway Traffic Safety Administration conduct a full investigation as soon as possible into the fire incidents. While we think it is highly unlikely, if something is discovered that would result in a material improvement in occupant fire safety, we will immediately apply that change to new cars and offer it as a free retrofit to all existing cars."
Not so fast, counters NHTSA head David Strickland. Speaking to The Detroit News, Strickland had this to say: "Investigations are independent... We have never ... actually had an automaker ask for a formal investigation, but it causes a couple of implications: If a manufacturer asks me or asks the agency for a formal investigation, you've already made a determination that you may have a defect that imposes an unreasonable risk to safety. ... I don't think that would ever happen."
It's important to remember that there were no serious injuries (let alone deaths) in any of the three Model S fires. Regardless of whether Tesla requested NHTSA's involvement or not, the fact remains that the Model S is being investigated, and we're all keenly interested to see the results.