(CNN) -- A California husband and father became the first TSA officer killed in the line of duty in the agency's 12-year history, the lone fatality in a frightful shooting at Los Angeles International Airport.
Gerardo Hernandez would have celebrated his 40th birthday next week.
Instead, he is being mourned as the first slain-on-duty officer at the Transportation Security Administration, a sometimes loathed but always vital agency that protects the country's airports.
"I am truly devastated," his widow Ana Hernandez said of the man she described as a "wonderful husband, father, brother, son and friend." "We are all heartbroken and will miss him dearly."
Contradicting reports that Hernandez was a behavior detection officer, TSA Administrator John Pistole said he had other duties.
TSA employees' union and federal sources said Hernandez was working as a travel document checker at the time of the shooting.
Union president J. David Cox Sr. said his group was "sickened" by the shooting and expressed thanks to "all our brave (transportation security officers) who put their lives on the line every day to keep the flying public safe."
The suspected gunman, 23-year-old Paul Anthony Ciancia, walked up to checkpoint at Terminal 3 where Hernandez was working, pulled a ".223-caliber MP-15 assault rifle out of his bag and fired multiple rounds at point-blank range," U.S. Attorney Andre Birotte Jr. said Saturday.
Ciancia, 23, then went up an escalator near the checkpoint but then came back down "to return and shoot the wounded officer again," Birotte added.
Hernandez was shot in the chest and abdomen, and pronounced dead upon his arrival at Harbor-UCLA Medical Center, CNN affiliate KABC reported. He had been with the agency since 2010, the affiliate said.
Two other TSA officers were also shot, one in the leg, authorities said.
"I'm shocked, the guy is a very nice guy," one of Hernandez's neighbors in the north Los Angeles community of Porter Ranch, Habib Bonakdar, told CNN affiliate KCAL-KCBS.
Hernandez was married with children, another neighbor, Ken Wong, told the affiliate.
"It's just tragic," Wong said. "What a terrible thing. Here's a man who was trying to serve his country, do his job well and support his family, and this is a senseless thing that happened. It shouldn't have happened."
CNN's Chelsea J. Carter and Greg Botelho contributed to this story.