Erika Yee and Chris Miller are connected in a way that may not be obvious.
The two University High School students are friends and in band and trigonometry classes together.
But in October they both experienced a "life-changing" event when Yee saved Miller's life.
On Monday, Yee, 17, was recognized with a copper plaque by Tucson Mayor Jonathan Rothschild for saving Miller's life with continuous chest-compression CPR.
"We are here to acknowledge Erika's heroic efforts," Rothschild said.
Miller, 16, stood close by looking at Yee during a ceremony at the mayor's office.
Miller, a sophomore, recalled the evening when he, Yee and other students were on campus for a function and were about to eat dinner.
Miller was standing in line to pay for his grilled burger, and talking to friends when he collapsed.
"A circle of people formed around him," said Yee, explaining that she saw the commotion and went to help.
She saw that Miller was seizing and wasn't breathing.
"He went into cardiac arrest," recalled Yee, a junior, who began chest-compressions until Tucson Fire Department paramedics arrived and took Miller to Tucson Medical Center.
"I woke up in a hospital bed, and people told me I had a seizure," said Miller, who did not remember passing out. Miller said he was treated at TMC before being transferred to University of Arizona Medical Center, where he underwent a series of examinations.
Doctors could not give him or his family a definitive answer about why he experienced a cardiac arrest, Miller said. But in case it happens again, doctors surgically placed a defibrillator under the skin below his collarbone to shock his heart into beating again, Miller said.
Miller said he does know two things - he is glad to be alive and to have Yee as his friend.
"We have known each other for quite some time. We are even closer now," Miller said.
Yee added: "This experience was life-changing. It is something that we won't forget."
Yee learned the lifesaving technique last summer at Camp Fury, a Girl Scouts firefighting camp.
The method has saved an additional 1,016 lives in Arizona in the past decade, said Dr. Karl Kern, a co-founder of chest-compression-only CPR.
All Tucson-area fire departments and about 80 percent of fire departments in Arizona use the method, said Kern, a professor and acting chief of the cardiology at the University of Arizona's Sarver Heart Center.
Kern said mouth-to-mouth CPR does have its role for infants and drowning incidents. "Unless there is a breathing problem, you don't need to do mouth-to-mouth CPR, Kern said.
Contact reporter Carmen Duarte at 573-4104 or email@example.com