The executive shuffle at Uber has officially begun. But the company faces an added challenge: a depleted leadership team.

Emil Michael, Uber’s SVP of business and right-hand man of CEO Travis Kalanick, has left the company after an investigation into sexual harassment and workplace culture at the startup.

The departure makes Michael the highest profile Uber exec yet to leave the company amid its ongoing PR crises, but he may not be the last.

On Tuesday, Uber will announce recommendations from an investigation overseen by former U.S. Attorney General Eric Holder. There have been reports that top officials, including Uber’s CTO and one of its board members, might be put under the microscope.

Uber’s board is reportedly considering a leave of absence for Kalanick following his mother’s death and father’s injury in a serious boating accident last month. Others have called for firing Kalanick outright.

All this uncertainty about the future of Uber’s leadership comes at a time when its bench of top executives is light — bordering on nonexistent.

“Uber is a company without a COO, CFO, CMO and soon to be SVP of Business,” James Cakmak, an analyst with Monness, Crespi, Hardt & Co, wrote in an investor note Monday shortly before Michael’s departure was announced.

“Who’s left?” Cakmak added. “Just the CEO, Mr. Kalanick. So, there really is no top brass at Uber.”

Put another way: a $68 billion startup with 14,000 employees and more than one million drivers seems to have almost no one at the steering wheel.

Reps for Uber did not immediately respond to a request for comment.

Related: Uber’s CEO is under fire. Can he hold onto his job?

In typical startup fashion, some C-Suite and board positions went unfilled for years.

“It’s a reflection of what you see in many founder-run companies: The founder has been given a lot of control,” says Jason Schloetzer, a professor at Georgetown who studies corporate governance. “There’s a lot of faith placed in his abilities to innovate and manage the firm as it continues to grow.”

Other top positions were vacated this year as Uber was hit by one negative headline after another.

Uber’s president quit in March due to concerns over the startup’s management culture. Its top finance exec left last month amid efforts to drive down its significant losses. Even the head of its self-driving car operation — an effort seen as Uber’s future — was recently fired.

That only makes it harder to push out Kalanick. He built Uber into a juggernaut by fundraising aggressively, dodging regulators and focusing on growth at all costs. It’s unclear who, if anyone, at the company would be fit right now to succeed him.

A source at Uber previously told CNN Tech there is a key effort underway to fill top leadership positions around Kalanick with seasoned executives. The hope, according to some Uber investors, is these executives can keep Kalanick in check.

Uber recently hired Frances Frei, a Harvard Business School professor considered to be a thought leader on organizational change, to take over as its SVP of leadership and strategy. It also poached Apple’s star executive Bozoma Saint John to take over as its first chief brand officer.

Uber has said it’s in the process of trying to hire for key positions including CFO, general counsel and COO. Kalanick said his goal for the COO role is to find “a peer who can partner with me to write the next chapter in our journey.”

Right now, it’s a little too lonely at the top.