May 11th, 2011
11:56 AM ET

GAO: Investigators drove 'explosive' into secure port

Washington (CNN) - Undercover government investigators were able to get into major U.S. seaports - at one point driving a vehicle containing a simulated explosive - by flashing counterfeit or fraudulently obtained port "credentials" to security officials - raising serious questions about a program that has issued the cards to more than 1.6 million people, Congress disclosed Tuesday.

At issue are Transportation Worker Identification Credentials, or TWIC cards, now needed by truckers, stevedores, longshoreman and others for unescorted access to the nation's ports.

The Department of Homeland Security has long touted the cards as one of the most important layers in its multilayered system to protect ports from terrorists. FULL POST