It appeared to be a typical Thursday for Theresa Byrne.
The Costa Mesa resident's days hadn't varied significantly in the nearly six months since her husband was deployed by the Air Force to Central Asia.
That was about to change.
With an anxious expression, Zachary Byrne straightened his camouflage cap, fitting it perfectly over his buz cut.
He held his young son close to his chest as he swung open the door of the Killybrooke Elementary School office.
Stepping out into the afternoon sunlight, he moved slowly with a nervous smile, eyes fixed on Theresa, her long, dark hair hanging over her blue polo shirt as she chatted with a fellow employee while watching a group of elementary students play on the nearby blacktop.
Theresa placed her hand over her mouth, unsure if the man before her was a apparition.
"I knew she wouldn't expect it," Zachary, an airman first class, said in an interview later. "I knew she would be focused on her work."