The Transportation Security Administration has identified a 39-year-old as the first officer killed in the line of duty in the agency's 12-year history.
The TSA says in a statement that Gerardo I. Hernandez is the officer who was slain by a gunman who opened fire at Los Angeles International Airport on Friday morning.
Two other TSA officers were wounded.
The gunman was wounded in a shootout with airport police and taken into custody.
The attack at the nation's third-busiest airport sent terrified travelers running for cover and disrupted more than 700 flights across the U.S.
TSA Administrator John Pistole said in a message to employees Friday evening that "no words can explain the horror that we experienced today."