Politico further points out that the emails were under subpoena at the time:
Clinton was under a subpoena order from the panel for all documents related to the 2012 attacks on the American compound there. But David Kendall, an attorney for Clinton, said the 900 pages of emails previously provided to the panel cover its request.
Kendall also informed the committee that Clinton’s emails from her time at the State Department have been permanently erased.
Depending on how this develops that could be obstruction of justice or some other criminal act.
