LOS ANGELES - A TSA agent checking passenger documents at a security checkpoint was killed Friday morning when a gunman armed with an AR-15 assault-style rifle opened fire inside Los Angeles International Airport, the third-largest airport in the nation.
"At 9:20 this morning, 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. He proceeded up into the screening area, where TSA screeners are, and continued shooting and went past the screeners back into the airport itself," said Chief Patrick Gannon, chief of airport police.
"Officers from airport police responded immediately to the calls. They tracked the individual through the airport and engaged him in gunfire in Terminal 3 and were able to successfully take him into custody," Gannon said.
He said the gunman "got back very far into the terminal." Later reports indicated he was shot near a Burger King near the end of the terminal.
ABC News initially reported that the gunman was killed, but officials said he was in critical condition Friday evening after he was shot by police officers.
Law enforcement officials identify the suspect as 23-year-old Paul Anthony Ciancia, of Los Angeles, formerly of New Jersey.
Friday night, TSA identified the officer killed as Gerardo I. Hernandez, 39.
Hernandez was the first TSA officer killed in the line of duty in the 12-year history of the agency, which was founded in the aftermath of 9/11.
The dead TSA employee was a behavior-detection officer, whose job is to spot suspicious activity to help detect possible terrorists, David Cox, president of American Federation of Government Employees. LAX has 2,157 TSA agents and about 1,100 Los Angeles police officers assigned to the airport.
Seven people were treated and six people were transported to the hospital, Los Angeles Fire Department's Jim Featherstone said. He said roughly 100 firefighter-paramedics were called to the mass emergency.
One male patient arrived in critical condition and two male patients are in fair condition, according to a statement from the UCLA Medical Center. Three others were transported to other area hospitals.
Most of the injuries were to people fleeing the gunman, officials said.
-- Lone shooter targeted TSA, witnesses say --
"We believe, at this point, there was a lone shooter," LAX's police chief, Patrick Gannon, said. "As we stand here right now, there is only one individual that is responsible for this ... as the active shooter."
Witnesses described the shooter as a short, young, white man, carrying a long-rifle and seemingly targeting TSA officers, ABC News reported.
Leon Saryan told ABC News Radio that a "fairly young" gunman with a rifle came down a corridor in Terminal 3 and shot perhaps 20 times.
"They told everybody to run towards the gates, and I couldn't run because I had my shoes and my belt off. So I was trying to gather up my stuff and get going and the TSA worker right behind me saw me and said, 'Get out of here, get down there.' He grabbed my shoes and I just started running.
"And I got halfway down the hall ... and I was in the hallway cowering when the guy came through ... And he had a rifle in his hand and he looked at me and he said 'TSA?' and I shook my head and he kept going."
Saryan is the father of a producer on Milwaukee radio station WTMJ. Listen to his complete interview with the radio station.
The TSA officer holding Saryan's shoes was shot and wounded, he told the radio station.
"I don't think he was seriously injured," Saryan said.
The TSA said "multiple" agents were hurt in the incident.
Gannon said police have conducted security sweeps through LAX and believe that the incident was isolated to Terminal 3 and the lone gunman.
The FBI is now leading the investigation since the airport is considered to be under federal jurisdiction.
"The crime scene is extensive," said David Bowdich, FBI Special Agent in Charge.
-- Witness describe chaos inside terminal --
Witnesses said that when the shots rang out inside the airport, hundreds of people started running.
"Just three loud pops and everybody started panicking," one witness said. "I laid down on the ground and luckily he just went straight through the security check and into the terminal. Mostly everybody just ran on their own."
"People were sprinting as fast as they could with their luggage. I guess it would have been more prudent to ditch our luggage, I suppose, but at the time, you just started running with whatever you had in your hands," one man said. "I got pulled into a hallway. We pulled a copier in front of the door, I was under a desk."
Another man said the dire situation prompted a security agent to open secure doors at the airport so they could flee.
"Security came and opened up the doors and we all piled onto the tarmac and just kind of hid underneath the plane," a witness said.
Xavier Savant was waiting in the security line at the terminal where the shooting occurred and he and other passengers dropped to the floor in panic. He described it as a "bam, bam, bam" burst of gunfire.
"We just hit the deck. Everybody in the line hit the floor and shots just continued," he said.
He said the shots subsided and people bolted through the metal detectors and ran into the terminal, eventually making their way out to the tarmac.
"My whole thing was to get away from him," said Savant, an advertising creative director in Hollywood who was heading to New York City with his family.
Grant Imahara of the Discovery show "Mythbusters" was in an airport lounge area when he heard gunfire in the terminal and saw police and terrified passengers react. "It was fairly tense and particularly after we heard the shots ring out, like 'Oh my God this is really happening,'" he said.
-- Statement issued by TSA, President briefed --
"This act of violence reminds us of the risks the brave men and women of TSA face every day as they work to protect the traveling public," acting secretary of the Department of Homeland Security Rand Beers said in a prepared statement.
"The thoughts and prayers of the entire Department go out to the family of the Transportation Security Administration employee who lost their life in the senseless shooting at Los Angeles International Airport earlier today, as well as the additional individuals, including TSA employees, who were injured in the incident," Beers said.
A statement issued by the White House Press Office said, "The President has been briefed about the shooting at LAX. We will continue to stay in touch with our federal and local partners. The LAPD is leading the response and investigation. We urge citizens to listen to the authorities and follow directions from the first responders on site. The president will continue to receive briefings throughout the day."
-- Flights delayed at LAX, elsewhere --
At least 746 flights were affected as a result of the shooting. Those include 65 arrivals and 61 departures canceled at LAX.
Flights were also put on hold from Denver International Airport to LAX.
Frontier Airlines flies into Terminal 3, where the shooting happened Friday morning. The airline tweeted around 1 p.m. "All flights in/out of LAX for today have been suspended."
LAX flights in terminals other than Terminal 3 have continued to take off at a slower pace but those who have flights at LAX later Friday were told to stay away and to call their airline.
"We're encouraging you at this point to stay away from the airport -- not because of the safety situation but because of the ongoing investigation makes it very difficult place to come to and to travel to," Los Angeles mayor Eric Garcetti said.
Terminal 3 will be closed indefinitely but the other terminals were in the process of reopening later Friday, Garcetti said.