A veteran Mesa firefighter died while on-duty Tuesday.
Keller passed away in the morning, according to a statement from Mesa Fire and Medical Department.
"We ask everyone to keep the Keller family in their thoughts today and support each other as we navigate this loss," the department said.
Posted on Facebook, Joleen Stonebraker Stratton shared: "This breaks my heart. We met him last summer when he responded to our 911 call when my son was choking on food. He was the nicest person. At the hospital he invited us to come see him at the fire station that coming weekend. We went there and he gave us a tour. We were so grateful for his help on one of our scariest days."

Peter Matthews | Editor-in-Chief/Conference Director
Peter Matthews is the conference director and editor-in-chief of Firehouse. He has worked at Firehouse since 1999, serving in various roles on both Firehouse Magazine and Firehouse.com staffs. He completed an internship with the Rochester, NY, Fire Department and served with fire departments in Rush, NY, and Laurel, MD, and was a lieutenant with the Glenwood Fire Company in Glenwood, NY. Matthews served as photographer for the St. Paul, MN, Fire Department.