All it took to draw the U.S. Justice Department into investigating Tesla Inc. was a single tweet by Chairman Elon Musk. But now that prosecutors have a toehold, they can dig in to look for other signs of misconduct at the electric car maker.

Tesla Inc. is under investigation by the Justice Department over public statements made by the company and CEO Elon Musk, according to two people familiar with the matter. The criminal probe is running alongside a previously reported civil inquiry by securities regulators.

The turmoil at Tesla Inc. reached a fever pitch, as the news that two senior executives are leaving Elon Musk’s electric-car maker emerged just hours after he smoked marijuana during an hours-long interview streamed live online.

SALT LAKE CITY — A Utah driver who slammed her Tesla into a stopped firetruck at a red light earlier this year while using the vehicle’s semi-autonomous function has sued the company, saying salespeople told her the car would stop on its own in Autopilot mode if something were in its path.

Officials at transportation service company Ruan got a chance to see Tesla Inc.’s prototype battery-electric heavy-duty truck, which toured the country recently, stopping at some carriers that have placed orders for the truck that is scheduled for fleet testing in 2019.

Tesla Inc.’s lead in battery technology gives it a cost advantage that may last for several years and help the U.S. electric-car maker face down an onslaught of new competition, according to new research from Bloomberg.

Elon Musk’s stunning tweet that he wanted to take Tesla Inc. private and had funding secured was a classic Musk moonshot — given credibility only by the sense that if anyone could possibly pull such a brazen feat, he was the guy.

Elon Musk has hired Morgan Stanley to assist him in his potential bid to take Tesla Inc. private, according to a person familiar with the matter.

What do you do when your CEO confesses that he’s cracking under the stress of his job? That’s the question that the nine board members of electric car and solar panel maker Tesla Inc. must answer after Elon Musk, the company’s impulsive leader, admitted to The New York Times that work is rattling his nerves in what he described as the most “difficult and painful year of my career.”

Tesla’s Elon Musk said in a blog post he reported the funding was secured for a go-private transaction after meeting with the Saudi Arabian sovereign wealth fund July 31, after the Saudi fund bought almost 5% of Tesla stock.