The nose of a 737 Max 8 plane destined for China Southern Airlines is seen at the Boeing Co. manufacturing facility in Renton, Wash., this month. (David Ryder/Bloomberg News)

After a pair of deadly plane crashes, Boeing is grappling with one of the biggest crises in its history.

Its 737 Max 8 jet has been grounded. Federal officials have launched a criminal investigation. And now at least one airline has canceled its order of the planes. The Chicago-based aerospace company has responded by defending its safety record, preparing a software update and updating pilot training material for the plane.

What Boeing has not done is update shareholders about these blows to its reputation. Since a Lion Air flight crashed shortly after takeoff into the Java Sea in Indonesia last October, Boeing has disclosed several important events to shareholders in the form of an 8-K filing to the Securities and Exchange Commission. It told investors when the company nominated former U.N. ambassador Nikki Haley to its board and about an increase its quarterly dividend.

But the company has not made a special announcement about the pair of deadly crashes or growing fallout.

Deciding what to tell shareholders and when can be tricky for corporate executives, securities experts say. The SEC requires companies to quickly alert shareholders of potentially market-moving news such a merger or the firing of a CEO. But they have more leeway when comes to rolling scandals.

The Justice Department, for example, has launched a criminal investigation surrounding the plane’s certification though the parameters of inquiry are still unclear. But such investigations often do not lead to any charges being filed, securities experts say. Requiring companies to alert investors of every government investigation could quickly become overwhelming, they say.

“The information is so limited that it is hard to say what will happen,” said Steven J. Durham, the former chief of the fraud and public corruption section at the U.S. attorney’s office in D.C.

Still, companies typically alert shareholders of government investigations though the timing can vary, said Harvey Pitt, who was SEC chairman under President George W. Bush. “It is generally considered good practice for companies to alert investors regarding the existence of a formal investigation at a point in time when the company understands the nature of the issues being investigated,” he said.

Given the moment-to-moment coverage the plane crashes have received, Boeing may not see a need to issue a special disclosure, Pitt said. “With something as open and notorious as Boeing’s current situation [Boeing] may view disclosure of an investigation as superfluous, although the existence of a criminal investigation is a significant development,” he said.

The grounding of such an important plane could have a significant financial impact on Boeing, Pitt said. Already, Indonesia’s national airline Garuda Indonesia is moving to cancel an order for 49 Boeing 737 Max 8 jet.

“My view is that Boeing should file an 8-K promptly to disclose any material contracts that are now in jeopardy as a result of the problems with the aircraft,” he said.

A Boeing spokeswoman pointed to a special website the company had created to provide updates on the crash, including an open letter from Boeing CEO Dennis Muilenburg.

“Safety is at the core of who we are at Boeing, and ensuring safe and reliable travel on our airplanes is an enduring value and our absolute commitment to everyone,” the letter says. Muilenburg also notes that regulators decide when to release details about the investigation.