A day before the sixth anniversary of the 9-11 attacks a Senate committee is holding a hearing to assess what the government is doing to protect the nation from another attack.

Top homeland security officials updated Congress on what has changed and what has not.

Airport baggage screening is tighter and so is the screening of passengers. Officials also say new carry-on rules have cut down the threat of bombs.

"No system works one hundred percent. But even if we're working ninety percent, that is a huge barrier to the enemy, which is planning to try to smuggle something on an airplane," said Michael Chertoff, Secretary of Homeland Security.

The government is still struggling to tighten other national security loopholes, from the porous borders and the sprawling ports to the identification cards we carry every day.

FBI director Robert Mueller says another emerging concern is home-grown radicals. He says he will be asking congress for additional domestic surveillance powers.