Ten Democratic senators accused Defense Secretary Mark Esper of leading a “disjointed and slow” Pentagon response to the coronavirus crisis that has passed the buck to lower-level commanders, confused U.S. troops and their families, and put their health second to the military’s ability to fight.

“We write to express our grave concern,” begins an eight-page letter sent to the Defense Department on Monday that argues civilian leadership has “failed to act sufficiently quickly” to direct the U.S. military’s response to the coronavirus.

“Your inability or unwillingness to issue clear, Department-wide guidance has forced the services and local commanders to make their own decisions on a case-by-case basis,” the lawmakers wrote. “The Department’s civilian leadership can and must do more to ensure the health of servicemembers and their families.”

The signatories include Sens. Elizabeth Warren and Edward Markey of Mass.; Mazie Hirono of Hawaii; Kamala Harris of Calif.; Patty Murray of Wash.; Richard Blumenthal of Conn.; Jeff Merkley and Ron Wyden of Ore.; Sherrod Brown of Ohio; and Amy Klobuchar of Minn. Warren, Harris and Klobuchar were all presidential primary candidates this year. Blumenthal, Hirono, and Warren are members of the Senate Armed Services Committee.

The Pentagon’s response to the COVID-19 crisis has been under particular scrutiny partly due to the controversy surrounding the outbreak on the USS Theodore Roosevelt, the aircraft carrier in the Pacific whose captain was fired after a letter warning Navy leaders that his crew was in danger appeared in the press. Additionally, service members and lower-echelon commanders have privately raised fears that the Defense Department wasn’t doing enough to protect them from the spread of the virus.

Esper has sought to push decision-making on COVID-19 mitigation efforts down to individual commanders at bases and on ships worldwide, whom Pentagon leadership believed were best positioned to decide what measures were necessary to protect service members under their authority. But that policy has caused confusion across the department and resulted in a mixed bag of policies that has endangered some troops, civilians and their families.

“Although local commanders know their units and operating environments better than anyone in the Pentagon, they are not public health experts. And they are now left to make decisions they should never have to make,” the lawmakers wrote. “Due to the lack of resources and the lack of guidance, the Department’s response has been disjointed and slow, risking the health of servicemembers and their families.”

The lawmakers also allege that Esper’s “tentative approach has also resulted in a series of contradictory decisions across the services.” They claimed also that recent remarks Esper made about lessons learned from the Roosevelt crisis “suggest a dangerous misunderstanding of the nature of COVID-19.”

“You said that the more than 600 positive cases aboard the USS THEODORE ROOSEVELT ‘has revealed a new dynamic of this virus, it can be carried by normal, healthy people who have no idea whatsoever that they’re carrying it.’ …But asymptomatic transmission was suspected as early as February 31 and evidence continued to build throughout February and March that asymptomatic transmission had occurred,” the letter reads.

“By mid-March it was extremely obvious. It is essential that Department leadership understand and act on the most recent and thorough understanding of the virus.”

Lawmakers are demanding the answers to 10 ten questions within two weeks, including the actual number of troops who have contracted the virus, plans for testing and screening personnel, access to the testing results of troops and family members outside of military healthcare facilities, what mental health services that are being offered, and the Pentagon’s plans for the next global outbreak.