WASHINGTON - For a small cadre of CIA veterans, the death of Osama bin Laden was more than just a national moment of relief and closure. It was also a measure of payback, a settling of a score for a pair of deaths, the details of which have remained a secret for 13 years.

Tom Shah and Molly Huckaby Hardy were among the 44 U.S. Embassy employees killed when a truck bomb exploded outside the embassy compound in Kenya in 1998.

Though it has never been publicly acknowledged, the two were working undercover for the CIA. In al-Qaeda's war on the United States, they are believed to be the first CIA casualties.

Their names probably will not be among those read at Memorial Day celebrations around the country this weekend. Like many CIA officers, their service remained a secret in life and death, marked only by anonymous stars on the wall at CIA headquarters and blank entries in its book of honor.

Their CIA ties were described to the Associated Press by a half-dozen current and former U.S. officials who spoke on condition of anonymity because Shah's and Hardy's jobs are still secret, even now.

The deaths weighed heavily on many at the CIA, particularly the two senior officers who were running operations in Africa during the attack. Over the last decade, as the CIA waged war against al-Qaeda, those officers have taken on central roles in counterterrorism. Both were deeply involved in hunting down bin Laden and planning the raid on the terrorist who killed their colleagues.

"History has shown that tyrants who threaten global peace and freedom must eventually face their natural enemies: America's war fighters, and the silent warriors of our Intelligence Community," CIA Director Leon Panetta wrote in a Memorial Day message to agency employees.

These silent warriors took very different paths to Nairobi.

Hardy was a divorced mother from Valdosta, Ga., who raised a daughter as she traveled to Asia, South America, and Africa over a long career. At the CIA station in Kenya, she handled the office finances, including the CIA's stash of money used to pay sources and carry out spying operations. She was a new grandmother and was eager to get back home when al-Qaeda struck.

Shah took an unpredictable route to the nation's clandestine service. He was not a soldier or Marine, a linguist or an Ivy Leaguer. He was a musician from the Midwest. But his story, and the secret mission that brought him to Africa, was straight out of a Hollywood spy movie.

"He was a vivacious, upbeat guy who had a very poignant, self-deprecating sense of humor," said Dan McDevitt, a classmate and close friend from St. Xavier High School in Cincinnati, where Shah was a standout trumpet player.

Shah - his given name was Uttamlal - was the only child of an Indian immigrant father and an American mother, McDevitt said. He had a fascination with international affairs. He participated in the school's model United Nations and, in the midst of the Cold War, was one of the school's first students to learn Russian. From time to time, he went to India with his father, giving him a rare world perspective.

"At the time, that was unheard of. You might as well have gone to Mars," said McDevitt, who lost touch with his high school friend long before Shah joined the agency.

Shah graduated from Berklee College of Music in Boston and Ball State University's music school. He taught music classes and occasionally played in backup bands for entertainers Red Skelton, Perry Como, and Jim Nabors. His doctoral thesis at Indiana's Ball State offered no hints about the career he would pursue: "The Solo Songs of Edward MacDowell: An Examination of Style and Literary Influence."

In 1987, after earning his doctorate, Shah joined the U.S. government. On paper, he had become a diplomat. In reality, he was shipped to the Farm, the CIA's spy school in Virginia.

In 1997, he was dispatched to headquarters as part of the Iraq Operations Group, the CIA team that ran spying campaigns against Saddam Hussein's regime. Around that time, the CIA became convinced that a senior Iraqi official was willing to provide intelligence in exchange for a new life in the United States. Before it could make that deal, the United States had to be sure the information was credible and the would-be defector wasn't really a double agent.

Somebody had to meet with the informant, somebody who knew the Middle East and could be trusted with such a sensitive mission. A senior officer recommended Shah.

The meetings were set up in Kenya, former officials said, because it was considered relatively safe from Middle East intelligence services.

Because of the mission's sensitivity, Shah bottled up his normally outgoing and friendly personality while at the embassy.