The controversy surrounding SignalGate has reached a boiling point, prompting the Defense Department’s inspector general’s office to launch an investigation. On Thursday, the office announced that it will examine Defense Secretary Pete Hegseth’s use of the Signal app to coordinate a military operation in Yemen with other Trump administration officials, which reportedly resulted in the deaths of at least 53 people, according to a BBC report.

In a memo addressed to Hegseth and Deputy Defense Secretary Steve Feinberg, Pentagon Inspector General Steven Stebbins stated that his office is initiating a “subject evaluation” to determine the extent to which the Secretary of Defense and other DoD personnel complied with departmental policies and procedures for using commercial messaging applications for official business.

The investigation was prompted by concerns from Republican Senator Roger Wicker, chairman of the Senate Armed Services Committee, and Democrat Jack Reed, the committee’s ranking member. They are likely worried that using a chat app to organize military operations may not be the most secure or transparent approach. Their concerns were exacerbated by a recent Politico report revealing that Trump’s national security team has set up at least 20 group chats on Signal to discuss various foreign policy initiatives, including military operations.

This probe may not have occurred if national security adviser Mike Waltz had not accidentally added The Atlantic’s editor-in-chief, Jeffrey Goldberg, to a group chat where Trump officials were discussing an attack on Yemen. Goldberg publicly disclosed the incident, leading to a contentious news cycle in which Hegseth and Waltz downplayed the severity of using a private chat app for war planning, with Waltz claiming that Goldberg had gotten “sucked into” the conversation.

Now that the incident has been made public, other questionable practices by the Hegseth-led Department of Defense have come to light, including the use of Signal and Gmail accounts to discuss sensitive information.

Such practices are generally frowned upon due to the risks they pose to national security, as emphasized in a Pentagon warning issued just days before the Yemen group chat incident. Additionally, using services like Signal and Gmail to discuss official business can compromise public transparency regulations, which require administrations to maintain proper records of such communications.

The outcome of the inspector general’s investigation will be interesting to see, assuming it is allowed to reach its conclusion without interference, given Trump’s history of ousting inspector generals.