LONDON (Bloomberg) - The U.S. military’s cyberwarfare unit is scrutinizing an unusually high number of deaths by suicide among personnel over a monthlong period this summer, according to government officials and other people familiar with the matter.

The deaths have worried U.S. lawmakers and military leaders within the secretive section of the armed forces, which defends American computer systems and hacks foreign adversaries, according to the people and records reviewed by reporters. They’ve also resurfaced officials’ longstanding concerns about the mental health of military hackers who have over the last year seen their workload surge because of foreign conflicts. 

Between early June and early July, as many as five people who worked in or closely with U.S. Cyber Command took their own lives, according to internal military communications, public records and the people. They spoke on condition that they not be identified because they weren’t authorized to discuss the matter. 

In June, Cyber Command’s leader acknowledged three suicides in an email to staff, said two of the people. Public records show two more suicides followed.

Suicide is rarely caused by a single event or circumstance, according to the U.S. Centers for Disease Control and Prevention. The military is actively investigating the circumstances of at least one of the recent deaths. Exactly what motivated these suicides isn’t clear from the records, and even to some of the people familiar with the deceased. 

Cyber Command personnel generally work far from the physical front lines of war in roles that are largely secret. In some cases, they suffer from insomnia, memory loss, rumination and physical illness, according to Erick Miyares, a psychologist and former military employee who was embedded at the National Security Agency, who conducted a 2025 study based on interviews with 50 U.S. cyberoperators. The army-funded study hasn’t been released due to security concerns, Miyares said.

This account is based on police reports, obituaries, state death records, internal military communications and interviews with more than a dozen people familiar with the suicides.

The quick succession of deaths has led Cyber Command to link them as a so-called suicide cluster, according to a person familiar with the matter. The Pentagon defines such clusters as suicides taking place closer together than normal and requires that they be addressed with specific actions.

Military hackers have seen their workload surge because of foreign conflicts, particularly the war against Iran. The deaths coincided with one of the most intense phases of the conflict.