It's humid and crowded at O'Hare International Airport's Gate K9 Thursday, and you can tell passengers just want to board their flight.
Yet suddenly smiles appear on faces, applause breaks out and people make way for Marine Cpl. Juan Rodriguez and his three-legged companion.
Half-bouncing, half-limping, Belgian Malinois Lucca is a hero -- one of an elite corps of military working dogs trained to sniff out ammunition, arms and explosives, and a veteran of tours of duty in Iraq and Afghanistan.
Lucca and Rodriguez switched flights at O'Hare Thursday en route to her next assignment, retirement in Helsinki, Finland.
Eight-year-old Lucca is not of retirement age, but a patrol in late March in Afghanistan's perilous Helmand province ended her career.
Lucca was off-leash, nose to ground, sniffing, as she's trained to do as a specialized search dog.
"She's very independent, obedient to the handler but not afraid to get out there," Rodriguez said.
Lucca detected a buried explosive, alerted the Marines and kept scouting for more. But the bomb was booby-trapped and as Lucca ran to look for more, a second exploded.
It was an excruciating moment for Rodriguez.
"I heard her squealing and screaming," he said. "I went up and gave her first aid and a tourniquet. I petted her to try and keep her calm.
"It was rough. Nobody else got hurt."
Lucca's wounds were so significant they required the amputation of her left front leg. During her time in Iraq and Afghanistan, she participated in more than 400 patrols with over 40 confirmed finds of explosives. The lives of Marines she saved can't be counted, officials said.
As a dog, she didn't understand what it was to fear, Rodriguez said. "Working dogs really want to please their handlers," he said. "They'll do whatever it takes."
At O'Hare, Lucca and Rodriguez were recognized at a ceremony and paraded to the gate with an honor guard of Transportation Security Administration officers.
Waiting for Lucca in Helsinki will be a familiar face -- Marine Gunnery Sgt. Christopher Willingham, head of security for the U.S. Embassy in Finland and a dad with two kids about to get a new best friend.
He also was Lucca's first trainer and served in Iraq with her. "She'll get a big surprise," Rodriguez said.
American Airlines is providing transportation for the two in cooperation with the charitable organization, Air Compassion for Veterans, which offers flights for the military, veterans and families who need medical care. American Airlines employees contribute to ACV through fuel-saving initiatives.
Ever the Marine, Rodriguez didn't elaborate on what saying goodbye will be like. "It will be hard," he acknowledged. But seeing Lucca bounce off to a safe home will ease the farewell.
Nonplused by all the strangers petting her at O'Hare's Terminal 3, Lucca worked away at a treat inside the treasured red toy she carried and kept close to her trainer. Rodriguez looked at his partner with love.
"She's back to normal," he said. "She hasn't skipped a beat."