By Dan Whitcomb and Alex Dobuzinskis
LOS ANGELES, Nov 1 (Reuters) - A lone gunman stormed into a packed terminal at the Los Angeles International Airport and opened fire with an assault weapon on Friday, killing an unarmed federal security agent before he was shot and captured, authorities said.
The gunfire in Terminal 3 touched off panic and chaos at one of the world's busiest airports as hundreds of travelers ran frantically for safety or dove for cover behind racks of luggage and loud alarms blared.
At least one airport security agent was wounded by gunfire, in addition to the one who was shot and killed, and a number of other people were hurt in the pandemonium.
Nearly 750 flights were halted, grounded or diverted as police evacuated passengers and shut down three terminals. Streets around the airport were blocked off for hours, snarling traffic for miles.
"An individual came into Terminal 3 of this airport, pulled an assault rifle out of a bag and began to open fire in the terminal," Patrick Gannon, chief of the Los Angeles Airport Police, said at a news conference.
Gannon said the gunman, a U.S. citizen who appeared to be acting alone, pushed through the screening gates and ran more than 100 yards (91 meters) into the airport, where law enforcement officers caught up with him in a food court, shot him at least once and took him into custody.
"The suspect got back very far into a terminal. There is a Burger King that is quite a ways away from the screening station, and he was able to get back there," Gannon said.
Special Agent David Bowdich of the FBI identified the suspect as 23-year-old Paul Anthony Ciancia, a resident of the Los Angeles area, who was being treated for his injuries at a local hospital. There were no further details on his condition.
The slain agent, 39-year-old Gerardo Hernandez, was the first from the Transportation Security Administration to die in the line of duty. The TSA runs passenger screenings in U.S. airports.
But the shooting was not the first such incident at the airport. In 2002, an Egyptian-born gunman opened fire at the ticket counter of Israeli airline El Al, killing a flight attendant and a passenger before he was shot and killed.
SOMEBODY YELLED RUN
At the airport, 47-year-old traveler Lauren Stephens said she had just put her luggage on the scale at the ticket counter at Terminal 3 on Friday when she heard a series of gunshots.
"Everybody hit the ground. I jumped over the desk where the conveyor belt is. The woman who was checking me in hit the ground, all the workers did. Everybody pancaked down on the ground," Stephens said.
"More gunshots started. Somebody just yelled 'Run' at the top of their lungs. It sounded like he was coming our way. I don't know if that was just because he was turning the gun around," she said. "I just left my bag and I just ran like hell. Everybody ran. People were falling. People were just trying to help each other out."
Video footage broadcast on CNN showed airport police shouting at travelers to get down as hundreds of people sprint past them, some carrying or dragging luggage. Loud alarms sound in the terminal and police sirens can be heard wailing outside.
Jose Mares, who was catching a flight back to his home in Oklahoma with his wife, told Reuters he was about 20 to 30 yards (18 to 27 meters) away from a man with a gun on the second level of Terminal 3 when the man opened fire. Mares, 31, said he used his own body to shield his wife from harm.
"As I'm getting on top of her I'm reaching for more luggage and that's when I stacked luggage like two high and then made a row of luggage," he said. "I was in the corner and I'm looking at the guy just shooting randomly, like I saw a TSA (agent) go down."
The FBI's Bowdich said the gunman shot at least two TSA employees, one fatally. A number of other people were injured while fleeing the scene.
Three men hurt at the airport were taken to Ronald Reagan UCLA Medical Center, where one was in critical condition and two others were in fair condition, according to hospital spokesman Mark Wheeler.
Los Angeles Mayor Eric Garcetti said that had police not moved to stop the gunman as quickly as they did, the carnage could have been much worse.
"There were more than 100 more rounds that could have literally killed everybody in that terminal today," he said.
The FBI said it would probe the shooting itself as well as the gunman's background, and a U.S. official who asked not to be identified said separately that federal investigators were trying to determine if the gunman had been targeting TSA agents.
"Our goal is to do a true scrub on the individual to find out what was the tipping point for this person," the FBI's Bowdich said.
A witness to the shooting, Leon Saryan, told CNN that the same man he had just seen shoot a TSA officer "calmly" walked toward him and asked, "TSA?"
"I just shook my head, and he kept going," Saryan said.
A photo of the suspect released by the FBI showed a young man with short, close-cropped dark hair and sideburns, and an FBI spokeswoman said agents armed with a search warrant were searching Ciancia's home in Los Angeles.
In New Jersey, where the suspected shooter's father lives, police and FBI agents descended on his family's home in Pennsville Township.
Pennsville Police Chief Allen Cummings said he had been contacted by Ciancia's father before the shooting, prompted by a worrisome text message from the young man to his brother.
"I came down here along with my lieutenant and we made a phone call to LAPD and asked that they do a well-being check on the son in Los Angeles, and they called me back and said he was not at home at the time," Cummings told Reuters.
He declined to elaborate on the nature of the text message but said family members told investigators they had no indication that Ciancia, who moved to California about 18 months ago, was troubled.
"Obviously they're upset. It's a shock to them. It's a shock to the community," Cummings said.
President Barack Obama was briefed on the incident and White House officials are in touch with law enforcement officials on the ground, spokesman Jay Carney told reporters.
"We're concerned about it, but I'll let law enforcement folks talk about it directly," Obama told reporters in the Oval Office after meeting with Iraqi Prime Minister Nuri al-Maliki.
Los Angeles International Airport is the world's sixth busiest, handling over 63 million passengers in 2012, according to its official website.