The head of the Federal Aviation Administration told Congress during a hearing Thursday about a midair collision over Washington, D.C., that killed 67 people that the agency must do more to ensure flying remains safe.

A federal official admitted mistakes were made in a Senate hearing on the midair collision at Ronald Reagan National Airport that killed 67 people, as lawmakers continue to press top aviation and safety officials for answers on the congested airspace.

If investigators were able to quickly find alarming data about the number of close calls in the years before the midair collision over the nation's capital that killed 67 people in January, then aviation safety regulators should have seen the problem,

The agency said it’s taking steps to lessen the risk of collisions, but lawmakers say too many gaps remain — and place part of the blame on the military.

Investigators have found that the Federal Aviation Administration had data showing the risk of a crash before the midair collision at Reagan National Airport.