(CNN)Here's what you might have missed Wednesday on CNN.
-- The FBI issues a rare public warning that it has "grave concerns" over the omission of key information in a controversial Republican memo about the agency's surveillance practices.
-- A train carrying Republican members of Congress to a legislative retreat in West Virginia hit a truck, sources said, leaving at least one person dead.
-- Dr. Brenda Fitzgerald, director of the Centers for Disease Control and Prevention, resigns following a news report over her purchase of tobacco stock after she assumed the role of running the nation's top health agency.
-- US Defense Secretary James Mattis is seeking a ban on cell phones at the Pentagon in the wake of security vulnerabilities discovered on other personal devices, according to three US defense officials familiar with an ongoing review of the issue.
-- Rep. Trey Gowdy, who gained national attention for his criticism of Hillary Clinton during a House probe into the 2012 attack on the US mission in Benghazi, Libya, is not seeking re-election.