Lt. Cmdr. Kevin J. Davis, call sign "Kojak," was flying the No. 6 plane with the Navy's Blue Angels at an air show April 21 in South Carolina when something went terribly wrong. For reasons still unclear, Davis' F/A-18 Hornet crashed in front of the crowd of 100,000. Among those in attendance were his parents, Jack and Ann Davis.

Davis, 32, was a second-year member of the Blue Angels. During his first year, he was the squadron's No. 7, meaning he served as the narrator when the Blue Angels performed, and flew media and VIP guests during single-ship demonstrations. This year, he was the No. 6 pilot, flying the opposing solo plane in demonstrations. Although the progression is not written in stone, next year Kojak would likely have moved up to fly No. 5, the lead solo plane, in what would have been his third and final year with the team.

Flying seems to have been in Davis' blood. He was one of three boys in a middle-class family, and he spent his youth in Massachusetts, where his father was a public school superintendent. As a teenager, he was active in the Civil Air Patrol. For college, he attended the Embry-Riddle Aeronautical University. After graduating with honors in 1996, he entered the Navy's Officer Candidate School. He earned his wings of gold - an extraordinary achievement in and of itself - in 1999.

Kojak flew the F-14 Tomcat, and, as part of the Red Rippers, was deployed to the USS Dwight D. Eisenhower and then the USS John F. Kennedy. He served in support of the war in Afghanistan. In 2003, Davis switched planes, moving to the Hornet. In 2004, he graduated from TOPGUN, the Navy's Strike Fighter Tactics Instructor program. Nine months later, he joined the Blue Angels. And while his death was accidental, Kevin Davis died a hero.

As a virtue, heroism is often invoked, but seldom properly appreciated, frequently being conflated with valor. Valor is a characteristic demonstrated in a specific instance, and it can be awesome to behold. To grasp a proper definition of valor, you need only browse the citations given to our soldiers, airmen and Marines ( Take, as just one example, Senior Airman Jason D. Cunningham. In March 2002, Cunningham was the medic on a mission to rescue two downed American pilots in Afghanistan. His helicopter was shot down by Taliban and al-Qaeda forces. His citation describes what happened next:

"Despite effective enemy fire, and at great risk to his own life, Airman Cunningham remained in the burning fuselage of the aircraft in order to treat the wounded. As he moved his patients to a more secure location, mortar rounds began to impact within 50 feet of his position. Disregarding this extreme danger, he continued the movement and exposed himself to enemy fire on seven separate occasions. When the second casualty collection point was also compromised, in a display of uncommon valor and gallantry, Airman Cunningham braved an intense small-arms and rocket-propelled-grenade attack while repositioning the critically wounded to a third collection point. Even after he was mortally wounded and quickly deteriorating, he continued to direct patient movement and transferred care to another medic." Cunningham saved the lives of 10 wounded soldiers that day in a stunning show of valor.

But there is a quieter, simpler heroism displayed every day by people like Kevin Davis, because the defense of a civilization is perilous work, even when no one is shooting at you.

Davis was the 26th member of the Blue Angels to die in the squadron's 60-year history. Flying a jet fighter with a top speed of 1,200 m.p.h. at low altitudes and in close quarters is dangerous in the best circumstances. But all military service is, by its nature, hazardous. About 613 of the deaths in Iraq have what the Pentagon classifies as nonhostile causes. On the second day of the Iraq war, for example, America lost one soldier, Lance Cpl. Eric James Orlowski, to an accidental weapons discharge, and another, Spec. Brandon Scott Tobler, in a vehicle crash.

Even in times of peace, soldiering is not like civilian work. Between 1983 and 1987, 11,216 service members died in accidents. As the Cold War ended and tensions eased, that number decreased, but still, between 1988 and 1996, 6,790 service members died accidentally in the line of duty.

For these men and women, it was an act of heroism simply to put on the uniform in the morning and go out into a dangerous world on behalf of their fellow citizens. The Roman historian Tacitus once observed: "In valor there is hope." And valor does give us that - hope that, in extraordinary situations, we might become, if only for an instant, more than ourselves.

But the simple heroism of Kevin Davis should be treasured as well. It gives us a template not for what we might become in extraordinary circumstances, but what, if we were our best selves, we might be every day.