Authorities say 23-year-old Paul Ciancia walked inside Terminal 3 at LAX and pulled an assault rifle from a bag. NBC's Miguel Almaguer reports. 
 
 A man carrying anti-government material and an assault rifle shot his way through security at Los Angeles International Airport on Friday, killing a Transportation Security Administration worker and wounding two others — after sending a suicidal text message to his family, authorities said. 
 
 NBC News Paul Anthony Ciancia 
 
 The gunman who sent travelers diving for cover and fleeing onto the tarmac — identified by authorities as 23-year-old Los Angeles resident Paul Anthony Ciancia — was shot in the chest by law enforcement and taken into custody in critical condition. 
 
 The TSA confirmed the identity of the slain officer as 39-year-old Gerardo I. Hernandez, according to an agency official. Hernandez is the first officer to have been killed in the line of duty in the agency's 12-year history. 
 
 Law enforcement officials said at a news conference Friday afternoon that the crime scene is extensive and that authorities are still investigating the suspect's background. While airport terminals 1 and 2 are being reopened, Terminal 3 remains shut down, officials said. 
 
 The motive isn't clear, but it's believed the suspect had anti-government views based on written materials he was carrying, the officials said. He texted his brother in New Jersey before the shooting and said he was thinking about killing himself, police told NBC Philadelphia. 
 
 Federal officials told NBC News it was unclear whether the gunman was targeting the TSA or was trying to shoot his way farther into the airport. But a witness said the shooter, calmly walking through the terminal with his weapon, approached him with a one-word question. 
 
 "All he said was, 'TSA?' Just like that," Leon Saryan told MSNBC. 
 
 The shooting started about 9:20 a.m. (12:20 p.m. ET) at Terminal 3, which serves Virgin America and other airlines. 
 
 NBC News Authorities believe the gunman used a a .223-caliber semiautomatic assault-style rifle. 
 
 The gunman walked through an "exit" lane reserved for passengers leaving the secure area of the airport, pulled the .223-caliber semiautomatic assault-style rifle out of a bag and opened fire at the security checkpoint, officials said. 
 
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 As he walked through the terminal, still firing, airport police pursued him. At a cluster of restaurants in the rear of the terminals, near the waiting area for some of the gates, they shot him several times in the chest, law enforcement sources said. 
 
 "He's been shot and he's been treated. He survived," Los Angeles Mayor Eric Garcetti said at the news conference. 
 
 The mayor added that the suspect had "more than 100 more rounds that could've literally killed everybody in that terminal today." 
 
 When the gunfire erupted, travelers who were waiting to snake through the security line suddenly had to abandon their suitcases and hit the ground. 
 
 "We were just standing there in line, and somebody started shooting," said Nick Pugh, a witness, who told NBC Los Angeles that he heard eight to 10 shots. "Everyone dropped to the floor and started crawling along the ground." 
 
 The shooting brought one of the nation's busiest airports to a standstill. 
 
 Eyewitness Leon Saryan talks about his experience at the Los Angeles airport and his interaction with the gunman. 
 
 Officials said 746 flights were affected, 46 of which were diverted. The rest were held on the ground in Los Angeles or at their originating airports, said Gina Marie Lindsey, executive director of Los Angeles World Airports. The ground stop applied to airports roughly west of and including Denver, officials said. It was imposed shortly after the shooting began and was lifted at 3 p.m. (6 p.m. ET) 
 
 "This has been a trying day for everyone, I know," Lindsey added. 
 
 The Federal Aviation Administration grounded flights at LAX, where 1,500 flights take off and land every day. Passengers heading there for departing flights were stuck in colossal traffic jams. Some abandoned their rides and rolled their suitcases the last distance to the airport. 
 
 Saryan said he was "cowering in a corner" when the gunman came over and asked whether he was with the TSA, even though he was in street clothes. 
 
 "He was calm. He was walking slowly," Saryan said. "He must have felt that he was in control, because he had his weapon and nobody else did at that time. 
 
 "But for the grace of God, you know, I would have been one of the fatalities," he said. 
 
 The airport said that seven people were injured in all but that the nature of all injuries wasn't clear. 
 
 A doctor from Harbor-UCLA Medical Center said two victims were taken there, including Hernandez, who was killed by a round that broke into fragments inside his torso, causing massive bleeding and chest and abdominal injuries. 
 
 Shooting suspect Paul Anthony Ciancia carried anti-government written material that was critical of the federal government and the TSA, officials say. NBC's Pete Williams reports. 
 
 Dr. David Plurad said that the victim didn't have a pulse when he arrived and that surgeons worked for more than an hour to try to revive him. 
 
 "We made every effort to stop the bleeding and get the heart to beat on his own," Plurad said. 
 
 The union that represents TSA workers told NBC Los Angeles that Hernandez was a behavioral detention officer who scanned passengers for unusual behavior and had been transferred to Los Angeles from Montana recently. 
 
 Another TSA worker was shot in the leg, said Nico Melendez, a spokesman for the TSA. 
 
 Brian Adamick, an accountant who was waiting for a flight to Chicago, spoke with a TSA agent with a leg wound on one of the buses that sped to the tarmac to evacuate passengers taking cover there. 
 
 "His right ankle is injured and he gets on and sits in the seat next to me, and I said, 'Are you OK?' He said: 'I'm fine. I got shot. Don't worry, I've been shot before,'" Adamick told NBC News in a telephone interview. 
 
 "I said, let me take a look, and he pulls up the pant leg and there's a flesh wound — 3 to 4 inches — looks like it's straight out of Hollywood, maybe a drop of blood or two," he said. 
 
 Another witness told MSNBC that there was an initial round of shots, then a pause, then more shots. An airline worker told travelers, "Go out! Go out!" and people streamed down the stairs and onto the tarmac for safety, he said. 
 
 Former Los Angeles and New York Police Chief Bill Bratton discusses the shooting that killed a TSA worker and wounded others at the Los Angeles airport. 
 
 Authorities said the suspect was living in Los Angeles but is originally from Pennsville, N.J., where his parents and brother still reside. 
 
 Pennsville Police Chief Allen Cummings said Ciancia texted his brother in the morning and said he was thinking about taking his own life. The family called local police, who alerted Los Angeles police. Officers went to Ciancia's apartment; he wasn't there, but his roommates said everything was fine, Cummings said. 
 
 President Barack Obama was briefed on the shooting, the White House said in a statement. Obama called TSA Administrator John Pistole to express his condolences to the family and friends of those injured, including the TSA employee who was killed in the line of duty, a White House official said. 
 
 In 2002, an Egyptian national opened fire at the El Al ticket counter at LAX, killing two Israelis before he was shot dead. Authorities ruled it a terrorist incident, even though the shooter was not tied to a known group. 
 
 Kristen Welker and Becky Bratu of NBC News contributed to this report. 
 
 This story was originally published on ||||| Gasaya Ichihara, left, runs across the street with her daughter, Sachika Ichihara, as they try to make their flight to Japan at Los Angeles International Airport on Friday, Nov. 1, 2013. Thousands of... (Associated Press) 
 
 A passenger walks with her luggage while leaving the Los Angeles International Airport on Friday Nov. 1, 2013. A suspected gunman was in custody Friday following a shooting at Los Angeles airport that... (Associated Press) 
 
 In this aerial video frame grab provided by CBS-LA, fire and rescue personnel gather at Los Angeles International Airport on Friday Nov. 1, 2013. Shots were fired Friday at Los Angeles International Airport,... (Associated Press) 
 
 In this photo provided by Natalie Morin, people stand on the tarmac after being evacuated from Los Angeles International Airport, Friday, Nov. 1, 2013, in Los Angeles, after shots were fired at Terminal... (Associated Press) 
 
 Los Angeles Police Chief Charlie Beck talks with other responders at Los Angeles International Airport on Friday Nov. 1, 2013. Shots were fired Friday at Los Angeles International Airport, prompting authorities... (Associated Press) 
 
 Passengers walk with their luggage leaving the Los Angeles International Airport on Friday Nov. 1, 2013. A suspected gunman was in custody Friday following a shooting at Los Angeles airport that left... (Associated Press) 
 
 A police officer closes a road at the Los Angeles International Airport on Friday Nov. 1, 2013, after shots were reporter in Terminal 3, prompting authorities to evacuate the terminal and stop flights... (Associated Press) 
 
 A police officer directs traffic at the Los Angeles International Airport on Friday Nov. 1, 2013, after shots were fired in Terminal 3, prompting authorities to evacuate the terminal and stop flights... (Associated Press) 
 
 Passengers are directed outside Terminal 2 at Los Angeles International Airport on Friday Nov. 1, 2013, after shots were fired, prompting authorities to evacuate a terminal and stop flights headed for... (Associated Press) 
 
 Passengers evacuate the Los Angeles International Airport on Friday Nov. 1, 2013, in Los Angeles. Shots were fired at Los Angeles International Airport, prompting authorities to evacuate a terminal and... (Associated Press) 
 
 Airplanes sit on the tarmac at Los Angeles International Airport Friday, Nov. 1, 2013. Thousands of fliers were delayed Friday after a shooting in Terminal 3 closed parts of the airport for hours, prompting... (Associated Press) 
 
 In this photo provided by John Forstrom, which has been authenticated based on its contents and other AP reporting, people wait at Gate 142 in Los Angeles International Airport, Friday, Nov. 1, 2013.... (Associated Press) 
 
 Passengers evacuate the Los Angeles International Airport on Friday Nov. 1, 2013, after shots were fired there, prompting authorities to evacuate a terminal and stop flights headed for the city from taking... (Associated Press) 
 
 Police stand on high alert at Terminal 2 at Los Angeles International Airport on Friday, Nov. 1, 2013. Shots were fired Friday at Los Angeles International Airport, prompting authorities to evacuate a... (Associated Press) 
 
 Passengers walk with their luggage while leaving Los Angeles International Airport on Friday Nov. 1, 2013. Shots were fired Friday at Los Angeles International Airport, prompting authorities to evacuate... (Associated Press) 
 
 Graphic locates LAX airport and terminal three where a shooting has injured multiple people and killed a TSA agent; 3c x 4 1/2 inches; 146 mm x 114 mm; (Associated Press) 
 
 A passenger walks with his luggage while leaving Los Angeles International Airport on Friday, Nov. 1, 2013. A suspected gunman was in custody Friday following a shooting at Los Angeles airport that left... (Associated Press) 
 
 Passengers evacuated from Terminal 1 wait outside Los Angeles International Airport on Friday Nov. 1, 2013. Shots were fired Friday at Los Angeles International Airport, prompting authorities to evacuate... (Associated Press) 
 
 Passengers evacuated from Terminal 1 wait outside Los Angeles International Airport on Friday Nov. 1, 2013. Shots were fired Friday at Los Angeles International Airport, prompting authorities to evacuate... (Associated Press) ||||| The young man believed to have carried out a shooting at Los Angeles International Airport had sent a sibling a text message mentioning suicide, leading their father to seek authorities' help in finding him, a New Jersey police chief said Friday. 
 
 Paul Ciancia's father called Pennsville Police Chief Allen Cummings early Friday afternoon saying another of his children had received a text message from the 23-year-old "in reference to him taking his own life," the chief told The Associated Press. 
 
 The elder Ciancia asked for help in locating Paul, Cummings said. The chief called Los Angeles police, which sent a patrol car to Ciancia's apartment. It wasn't clear whether the police visited before or after the airport shooting. 
 
 "Basically, there were two roommates there" Cummings said. "They said, `We saw him yesterday and he was fine.'" 
 
 He told Cianci's father that because of his son's age, he couldn't take a missing persons report. 
 
 A law enforcement official speaking on condition of anonymity identified Paul Ciancia as the man who pulled a semi-automatic rifle from a bag and shot his way past a security checkpoint at the airport, killing a security officer and wounding two other people. 
 
 The gunman was wounded in a shootout with police and was taken into custody, Los Angeles police said. 
 
 The official who identified Ciancia was briefed at the airport on the investigation and requested anonymity because was he was not authorized to speak publicly. 
 
 A motive wasn't immediately clear. The shooter was wearing fatigues and carrying a bag containing a handwritten note that said he "wanted to kill TSA and pigs," the official said. 
 
 A second law enforcement official confirmed the identity, speaking on condition of anonymity because he was not authorized to discuss the investigation publicly. 
 
 The Pennsville police department has had no dealings with the younger Ciancia, Cummings said. 
 
 Outside the father's home Friday in Pennsville _ in southern New Jersey across the Delaware River from Wilmington, Del. _ a police cruiser blocked the long driveway to the home, which isn't visible from the road. Phone calls weren't answered, and efforts to reach siblings were also unsuccessful. 
 
 Neighbor Josh Pagan, 17, said that he would sometimes encounter Ciancia at orthodontist appointments, but that it had been at least two years since the last one. 
 
 "He was never weird toward me. He never gave me any weird vibes," he said, adding that in the 10 years he's lived across the street from the Ciancia family "they've been nothing but nice to us." 
 
 Ciancia's father owns an auto body shop, Cummings said. 
 
 "I've been here 23 years and they are a good family," he said. 
 
 ___ 
 
 Rubinkam reported from Pennsylvania. Associated Press writer Tami Abdollah in Los Angeles and Alicia Caldwell in Washington contributed to this report.
– We've got a name but still no real explanation of why a shooter opened fire at LAX today. Authorities have identified the gunman at Los Angeles International Airport as 23-year-old Paul Ciancia. A law-enforcement official says Ciancia was carrying a note that said he "wanted to kill TSA and pigs," reports AP. One witness tells NBC News that the gunman approached him calmly in the airport while carrying his weapon. "All he said was, 'TSA?' Just like that." (The one person killed in today's shooting was a TSA employee.) Not much is known about Ciancia at this point, but a separate AP story has this surprising nugget: His father in Pennsville, NJ, called police there this afternoon because Ciancia had texted one of his siblings suggesting he was about to kill himself. The New Jersey chief called the police in LA, who sent a patrol car to his apartment. He wasn't there. "Basically, there were two roommates there," says the Pennsville chief. "They said, 'We saw him yesterday and he was fine.'"