Three State Department staff resign after scathing report blasts State over Benghazi consulate attacks (VIDEO)

An official report has harshly criticized the State Department for "grossly inadequate" security at America's mission in Benghazi during the Sept. 11 attacks that killed US Ambassador to Libya Chris Stevens and three others.

The leaders of an independent panel issued the scathing assessment that, according to an unclassified version of the report, found "leadership and management deficiencies at senior levels" in the department and "real confusion" in Washington and in the field over who could — and should — have made decisions involving security.

According to that version of the report, the board also found that protests did not precipitate the attacks. "The Board concluded that there was no protest prior to the attacks, which were unanticipated in their scale and intensity," the report states.

The findings of the Accountability Review Board, some of which are classified and will only be heard behind closed doors before the House and Senate foreign affairs committees, may taint the four-year tenure of Secretary of State Hillary Clinton, Reuters wrote.

The Associated Press reported on Wednesday that three State Department officials resigned over the report. An official told CNN that two of the those who resigned were Eric Boswell, assistant secretary of diplomatic security, and Charlene Lamb, deputy assistant secretary of state for international programs, both of whom were responsible for security at the Benghazi mission. The official said a third person had resigned from the Near East Affairs bureau.

Clinton, who suffered a concussion last week after fainting and is currently ill, was scheduled to testify at Thursday hearings about the Benghazi attack. She is no longer expected to attend — her deputies are scheduled to testify on her behalf — but Republican senators said Wednesday they still want to hear from Clinton.

“I think it’s very, very important that she come before the committee," Tennessee Sen. Bob Corker, expected to be the lead Republican on the Senate Foreign Relations Committee next year, told Politico.

Sen. Dick Durbin told the news outlet, "I hope that Secretary Clinton will be able to testify.”

It appears Clinton has been active from her sick bed, however. In a lengthy letter sent after Wednesday's release of the report to John Kerry — chairman of the Foreign Relations Committee and a frontrunner to replace Clinton as secretary of state — Clinton didn't shy away from the report's recommendations.

"The Acccountability Review Board report provides a clear-eyed look at serious, systemic challenges that we have already begun to fix," Clinton wrote. "I am grateful for its recommendations for how we can reduce the chances of this kind of tragedy happening again. I accept every one of the them."

The Secretary went on to detail the steps the State Department has taken since Sept. 11 to address security problems at diplomatic posts.

According to CNN, the panel's 39-page, unclassified version of the report concluded that "systemic failures" resulted in a security plan "that was inadequate for Benghazi and grossly inadequate to deal with the attack that took place."

The Clinton-appointed panel, whose members include veteran diplomat Thomas Pickering and former Joint Chiefs of Staff Chairman Adm. Mike Mullen, found that the State Department showed "a lack of proactive leadership and management ability," Bloomberg wrote.

Nor was there any US or allied intelligence warning of the attacks, in which armed men breached the US mission's compound walls, the report noted.

However, it added, no single government employee breached his or her duties in the lead-up to the attacks.

There was no "evidence of any undue delays in decision making or denial of support from Washington or from the military combatant commanders" involved in evacuating US government personnel from Benghazi within 12 hours of the attack, according to the report.

There simply wasn’t enough time for any US military response to have made a difference, the panel found.

The board cited a lack of resources as partly to blame:

"The solution requires a more serious and sustained commitment from Congress to support State Department needs."

More from GlobalPost: Benghazi attack 'deliberate, organized terrorist' act, US intelligence director says