LOS ANGELES -- A man carrying a bag with a hand-written note that said he "wanted to kill TSA" opened fire with a semi-automatic rifle at a security checkpoint at Los Angeles International Airport on Friday, killing a TSA officer and wounding at least three others, authorities said.
The gunman, wounded in a shootout with police, was taken into custody, authorities said. The Transportation Safety Administration officer was the first killed in the line of duty in the 12-year history of the agency, which was founded in the aftermath of the Sept. 11, 2001 terrorist attacks.
The attack sent terrified travelers running for cover and disrupted flights from coast to coast, authorities said.
A law enforcement official said the suspect, Paul Ciancia, 23, from Pennsville, N.J., was wearing fatigues and carrying a bag containing the hand-written note. The official was briefed at LAX on the investigation and requested anonymity because was he was not authorized to speak publicly.
A second law enforcement official confirmed the identity, also speaking on condition of anonymity because he was not authorized to discuss the investigation publicly.
Pennsville Chief Allen Cummings said Paul Ciancia's father called him early Friday afternoon saying another of his children had received a text message from the suspect "in reference to him taking his own life." Cummings said the elder Ciancia asked him for help in locating Paul, according to Cummings.
The chief said he called Los Angeles police, which sent a patrol car to Ciancia's apartment. There, two roommates said they had seen him Thursday and that he was fine.
Cummings said he told Ciancia's father that because of the son's age, he couldn't take a missing persons report. He said Ciancia's father owns an auto body shop. He says they are a "good family" and that his department had no dealings with the younger Paul Ciancia.
Los Angeles Airport Police Chief Patrick Gannon said that around 9:20 a.m., the gunman pulled what he described as an "assault rifle" from a bag and began firing inside Terminal 3. He then went to the security screening area, where he fired more shots and went into the secure area of the terminal, Gannon said.
Officers exchanged fire with the gunman and apprehended him. Police believe he was the only shooter, Gannon said.
"As you can imagine, a large amount of chaos took place in this entire incident," he said.
As gunshots rang out, panicked fliers dropped to the ground. Those who had made it past security fled onto the tarmac or sought cover inside restaurants and lounges.
"We just hit the deck. Everybody in the line hit the floor and shots just continued," said Xavier Savant, who was waiting in the security line where the shooting occurred. He described it as a "Bam! Bam! Bam!" burst of gunfire.
Savant 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 who was heading to New York with his family for a weekend trip.
As police searched for other shooters, they escorted travelers out of the airport. Aviation officials stopped flights destined LAX from taking off from other airports, causing delays across the country. Some flights also had to be diverted to other airports.
It was not the first shooting at LAX. On July 4, 2002, a limousine driver opened fire at the airport's El Al ticket counter, killing an airline employee and a person who was dropping off a friend at the terminal. Police killed the man.
The TSA officer shot at LAX airport was the first ever killed in the line of duty, union and TSA officials said. At least three other TSA officers were also injured, said J. David Cox Sr., national president of the American Federation of Government Employees.
The officer who was killed was a behavioral detection officer, Cox said. Those officers are stationed throughout the airport looking for suspicious behavior, he said.
Ben Rosen was sitting at the Starbucks eating oatmeal when he heard gunfire erupt and people start running in all directions and others crouching on the ground. Rosen got on the ground and another passenger said: "Don't worry, we're safe."
Then, more gunshots erupted. He grabbed his phone and tried to lie as flat on the ground as he could.
Police showed up with their guns drawn, shouting, "This is not a drill! Hands up!"
Everyone put their hands up and then were led out of the airport terminal to the international terminal, Rosen said. As they were led out they saw broken glass from a window that looked like it'd been shot out. Rosen left his bag behind.
Six people were taken to the hospital, the Los Angeles Fire Department said. It's unclear whether the gunshot victims were among the group.
Bay Area airports were urging travelers to check with their airlines for potential delays and cancellations as the FAA has slowed traffic in and out of LAX.
Los Angeles International is by far the most popular U.S. destination for Bay Area airports, with 2.5 million annual passengers traveling between LAX and San Francisco, Oakland and Mineta San Jose international airports.
"The possibility of delays and cancellations to and from LAX is certainly there," said Doug Yakel, spokesman for SFO, the biggest Bay Area airport. He did not immediately have numbers of canceled or delayed flights. "So our best advice is for passengers to check with their airlines."
At SFO, San Francisco police said it had deployed all available resources to patrol terminals "in an abundance of caution."
Oakland airport officials said their 19 flights a day to LAX, on Southwest and Delta airlines, do not go into Terminal 3, where the shooting happened. As a result, the airport has not noticed any delays as of late morning but was monitoring for potential problems.
At San Jose airport, one flight headed to LAX was still at the gate before 11 a.m. Two of the six airlines that operate 29 flights from San Jose to Los Angeles daily had reported delays while the airport was bracing for the worst from the other four.
Virgin America and Southwest Airlines had both asked to land LAX-bound flights at San Jose airport, where pilots were waiting for clearance to head to Los Angeles.
San Jose airport spokeswoman Rosemary Barnes urged passengers to be patient when trying to get information from their airlines.
"I'm sure they'll be bombarded with calls today," Barnes said.
LAX's Terminal 3 is handles flights by AirTran, Alaska, Horizon, JetBlue, V Australia, and Virgin America airlines.
Staff writer Mike Rosenberg contributed to this report. Follow him at twitter.com/RosenbergMerc.