Under intense criticism, Secretary of Veterans Affairs Eric Shinseki testified to a Senate panel on Thursday that he was “mad as hell” about claims of falsified waiting lists and cover-ups at VA medical centers, and vowed to fix the problems after an investigation by the inspector general’s office.

Shinseki faced tough questioning from the Senate Veterans Affairs' Committee at the first hearing since allegations surfaced that 40 veterans died at a Phoenix hospital while awaiting care and that employees engaged in a scheme to hide records that patients in six states had waited too long for medical attention.

"I am personally angered and saddened by any adverse consequence that a veteran might experience while in, or as a result of, our care," Shinseki said in opening remarks.

Committee members thanked Shinseki for his service and dedication during his 38 years in the Army and in his current position as head of VA, but their questions and comments were pointed. 

Sen. Patty Murray, D-Wash., said the allegations that the VA intentionally hid delays in treatment that in some cases may have resulted in veteran deaths were “deeply disturbing,” and added, “We need more than good intentions.” Instead, she called for “decisive action.”

VA health care facilities in Florida, Georgia, Pennsylvania, South Carolina and Washington have been singled out for unacceptably long delays for veteran care and poor oversight. During the hearing, Shinseki acknowledged that he was aware of past record-keeping problems.

Since CNN broke the story about three weeks ago, eight more health care facilities have been accused of tampering with data, including accusations on Tuesday by former employee Germaine Hines, who said that lists were being manipulated by VA hospital administrators "to make numbers look better for their own recognition and for bonuses.”

In response to committee members' demands, Shinseki said he would take "timely action" to deal with the allegations, but offered few details. His mild manner and earnest promises did little to quell the committee members' anger over the VA's problems. He did not appear to have much of the information the committee was looking for, and frequently turned to Dr. Robert Petzel, his undersecretary for health, for answers.

Sen. Richard Blumenthal, D-Conn., went so far as to suggest that “federal criminal authorities” should be called in to investigate the alleged falsification of government documents. 

Shinseki is now to appear before the House Veterans' Affairs Committee, which issued a subpoena for all emails by VA executives from April 9 to the present day that discuss the destruction or disappearance of a so-called secret list of veterans waiting for treatment at the Phoenix VA. 

The Office of the Inspector General has asked the House not to disclose the contents of the emails until their probe into the deaths and possible cover-ups at the hospital has been completed. The secretary’s deadline for providing the information is Tuesday at 9 a.m. EDT.