LOS ANGELES (USA Today) -- A deadly shooting spree at crowded Los Angeles International Airport by a lone gunman left a security official dead and a half-dozen other people injured Friday, creating scenes of mayhem that sent hundreds scurrying and snarled travel plans for thousands more.
The FBI identified the shooter as 23-year-old Paul Ciancia Jr. of Los Angeles. Police said he fired a series of shots from an assault rifle in LAX Terminal 3 at 9:20 a.m. and was apprehended after being shot by authorities.
PHOTOS | Shooting at Los Angeles International Airport
The dead TSA officer, Gerardo I. Hernandez, 39, was a behavior-detection officer tasked with spotting suspicious activity and identifying potential terrorists, said TSA Administrator John Pistole.
Hernandez is the first TSA officer killed in the line of duty in the 12-year history of the agency, created after 9/11. Another victim was listed in critical condition, and at least two of the injured were TSA employees.
"No words can explain the horror that we experienced today when a shooter took the life of a member of our family and injured two TSA officers at Los Angeles International Airport," Pistole said late Friday.
Pistole said he would travel Saturday to Los Angeles to meet with Hernandez's family and the local TSA workforce.
Investigators recovered a rambling message from the bag the shooter was allegedly carrying, which detailed an intent to "kill" TSA officers, said two federal law enforcement officials familiar with the message's contents. The officials, who are not authorized to comment publicly, said it was written in way that suggested the author expected to lose his life.
One of the officials described the incident as a suicide mission.
In recent days, one of the officials said, the New Jersey family of the alleged shooter had become worried about his emotional state and called local police, who relayed their concerns to Los Angeles authorities. The official said Los Angeles police reportedly were in contact with the alleged shooter's roommates, who indicated that he appeared to be OK.
The suspect entered Terminal 3, pulled out an assault rifle from a bag, then began to open fire at a screening checkpoint, according to LAX Police Chief Patrick Gannon. He then proceeded up to a screening area, where he continued shooting, then went past the screeners back into the airport itself, Gannon said. He continued to move along a terminal corridor until apprehended at a Burger King in the food court.
Before arriving in the LA area, Ciancia lived with family in a quiet, wooded neighborhood in Pennsville, N.J., police said.
Joshua Pagan, 17, has lived across the street from Ciancia's residence in Pennsville for the past 10 years. He said Ciancia has a brother close in age to him.
"I've seen (Paul) a few times, but I did not know him personally," Pagan said. "From what I've seen and heard, he was just a normal person - just an every-day guy. Right now, I am still trying to process this. Did this really happen? Did they get the wrong guy? Because if they told me they got the wrong guy, it would make a lot more sense to me."
The shooting left much of the nation's third-busiest airportshut and the surrounding area in gridlock. The Federal Aviation Administration canceled or diverted 746 flights. Airport roadways were closed. Travelers were stuck on incoming and departing planes on the tarmac, on buses or sidewalks.
Monitored in real-time by scores of terrified bystanders on social media websites such as Twitter and Instagram, the incident was the latest in a recent spate of mass shootings. Some passengers built walls of luggage to protect themselves from flying bullets. Others fled through emergency doors and onto the tarmac, including some who were briefly handcuffed and questioned by swarming groups of police before they were released.
"They probably thought I was the shooter. They handcuffed me and told me not to move," said Nick Pugh, who was attempting to fly to New York to watch Sunday's New York Marathon.
Aleksander Fiksdal, 22, was in a security checkpoint line for a flight to his native Norway when he heard shots ring out. "I turned and saw a guy with a rifle and I threw myself on the ground," Fiksdal said. Other passengers in the security line did the same, while some broke and ran.
Miguel Suarez, 32 of Mexico City said he was in line at the Aeromexico counter when he heard gunfire erupt. "When I looked where the sound came from, (everyone) just started running. It was just panic," he said.
Friends Mara Allen, 42, of Yuba City, Calif., and Vicki Powell of Sacramento had just arrived on a flight so they could go on a cruise to celebrate Powell's 50th birthday. Gathered with others around a baggage carousel, they were startled when a police officer started yelling for people to flee. Wheelchair-bound Powell wasn't sure how she was going to get out.
"I was waving. Come get me. Help!" Powell caught the attention of an attendant who wheeled her outside. The pair had to leave their luggage behind, and it was unclear whether they'd be able to retrieve it before their ship leaves LA for Mexico. "This is something I see on TV. I don't want to be in it," Powell said.
"It was like a dream, a movie. It was intense. We all sort of panicked. I'm shaking and scared. I don't know if we're still safe," passenger Audrey Henry told Fox News after fleeing the terminal. Her husband, Mark, said the couple were unsure when they would be able to recover their baggage. "We just ran," Mark Henry said.
The Radisson Hotel close to LAX was turned into a makeshift refugee center crammed with passengers. One large group gathered around a television set in the bar, where a clot of them were glued to coverage of the unfolding drama.
The last shooting at the airport occurred in July 2002, when an Egyptian immigrant shot and killed two bystanders in a rampage at the El Al ticket counter.
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