A man toting a semi-automatic rifle, some 150 rounds of ammunition and a grudge against federal security agents shot his way past a security checkpoint at Los Angeles International Airport in a deadly rampage that sent hundreds of travelers fleeing in terror.

When the shooting stopped, a Transportation Security Administration officer was dead. Gerardo I. Hernandez, 39, became the first TSA officer in the agency's 12-year history to be killed in the line of duty. The agency was founded in the aftermath of the Sept. 11, 2001, terrorist attacks.

Five other people were hurt, including two other TSA employees and the gunman, identified as Paul Ciancia, 23, of Pennsville, New Jersey. He was shot four times, including in a mouth and leg, by airport police and remained hospitalized but there was no word on his condition.

An estimated 1,550 scheduled arriving and departing flights with around 167,000 passengers were affected, according to the airport. That included 86 arriving flights that were diverted to other airports.

As gunshots rang out in Terminal 3 on Friday morning, swarms of passengers screamed, dropped to the ground or ran for their lives.

"I really thought I saw death," said Anne Rainer, who witnessed the gunfire with her 26-year-old son Ben. The pair were about to leave for New York so her son could see a specialist for a rare genetic condition he has.

They took refuge behind a ticket counter where she said people prayed, cried and held hands. She watched as one person jumped from a second-floor balcony to get away from the gunman.

"Adrenaline went through my head, my body went numb, and I said, `If I have to go, it's OK because I'm not going to feel it, but I have to save him,'" Rainer said.

Others fled into the terminal, taking refuge in coffee shops and lounges as the gunman shot his way toward them. However, some witnesses and authorities said the gunman ignored anyone except TSA targets.

A law enforcement official said the gunman was dressed in fatigues and carried at least five full 30-round magazines of ammunition. In his bag he had a one-page, handwritten note that said he wanted to kill TSA employees and "pigs."

The official, who was not authorized to discuss the investigation publicly and spoke on condition of anonymity, said the note referred to how the gunman believed his constitutional rights were being violated by TSA searches and that he was a "pissed-off patriot" upset at former Homeland Security Secretary Janet Napolitano.

On Friday, Ciancia's father in New Jersey had called authorities for help in finding his son after the young man sent one of his siblings a text message about committing suicide, Pennsville Police Chief Allen Cummings said.

The chief said he called Los Angeles police, who sent a patrol car to Ciancia's apartment. There, two roommates said that they hadn't seen him a day earlier and he had appeared to be fine.

Cummings said that the Ciancias _ owners of an auto body shop _ are a "good family" and that his department had had no dealings with the son.

The attack at the nation's third-busiest airport _ which is a major gateway for flights to Asia, Australia and New Zealand _ began around 9:20 a.m. when the gunman pulled the assault-style rifle from a bag he had carried into the terminal, which serves such airlines as Virgin America, AirTran, Horizon Air and JetBlue.

Airport police were running after the gunman within seconds of the first shots being fired, Chief of Airport Police Patrick Gannon said.

Friends and neighbors remembered Hernandez, the officer who died in the shooting, as a doting father of two and a good neighbor went door-to-door warning neighbors to be careful after his home in the Porter Ranch area of Los Angeles was burglarized.

President Barack Obama called the head of the Transportation Security Administration to express his condolences to the families and friends of the dead and injured TSA officers.

In all, five people were taken to hospitals. They included Hernandez, Ciancia, the two wounded TSA officers, and a person who suffered a broken ankle during the chaos. A sixth person was treated at the scene for ringing in the ears from gunfire, the Los Angeles Fire Department said.

Among the people evacuated from the airport, more than dozen were treated for minor injuries such as twisted ankles, exhaustion or stress.

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.

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Associated Press writers Joan Lowy and Alicia Caldwell in Washington; Greg Risling, Christopher Weber, Alicia Chang, Alicia Rancilio, Gillian Flaccus and Michael R. Blood in Los Angeles; Josh Hoffner in Phoenix; and Michael Rubinkam in Pennsylvania contributed to this report.