LOS ANGELES, Nov 02, 2013 (AFP) - Police were hunting for a motive Saturday after a gunman opened fire at Los Angeles International Airport, killing an unarmed federal official, terrifying hundreds, and sowing chaos at the busy transport hub.
Panicked travelers scrambled to escape after the shooter - identified as 23-year-old Paul Anthony Ciancia - armed with an assault rifle, blasted through a security checkpoint at the airport shortly after 9:00 am (1600 GMT) Friday.
Ciancia then walked calmly through the terminal seeking further victims. He was eventually stopped when police shot and wounded him.
TV footage showed people diving to the floor at the sound of gunfire and scrambling to escape the terminal.
The dead agent was the first Transportation Security Administration (TSA) employee killed in the line of duty since the group was set up following the September 11, 2001 terrorist attacks.
The lone gunman, who reportedly had a grudge against the TSA, also wounded seven people in the rampage.
But he was still carrying plenty of ammunition when he was arrested, said Los Angeles Mayor Eric Garcetti.
"There were more than 100 more rounds that could have literally killed everybody in that terminal today," he said, praising airport police. "If it were not for their actions, there could have been a lot more damage," he said.
"My prayers are with the TSA family today and with your fallen. Thank you for your courage and your service. Our country is indebted," Garcetti later wrote on his Facebook account.
The mayor also ordered flags on city buildings to fly at half-mast in honour of the slain TSA agent.
While reports suggested Ciancia - who was shot several times before he went down - was a disgruntled loner, the Federal Bureau of Investigation said it could not rule out terrorism.
The shooter opened fire in a crowded terminal of the country's third-busiest airport.
He "came into Terminal Three, pulled an assault rifle out of a bag and began to open fire," said Patrick Gannon, head of the airport police.
"He proceeded up into the screening area ... and continued shooting," he said.
Police chased the gunman, "engaged him in gunfire... and were able to successfully take him into custody."
The terminal remained close Saturday as authorities carried out a detailed investigation of the shooting.