WASHINGTON — In the fall of 2001, a soft-spoken economics major named Elizabeth Hanson set out to write her senior thesis at Colby College in Maine. Her report, “Faithless Heathens: Scriptural Economics of Judaism, Christianity and Islam,” may have given a hint of her career to come, as an officer for the CIA specializing in hunting down Islamic extremists. That career was cut short last week: Hanson was one of seven Americans killed in a suicide bombing at a CIA base in Afghanistan.

In the days since the attack, details of the lives of the victims — five men and two women, including two private contractors for the firm formerly known as Blackwater — have begun to trickle out, despite the secretive nature of their work.

What emerges is a rare public glimpse of a closed society, a peek into one sliver of the spy agency as it operates more than eight years after the CIA was pushed to the front lines of war.

Their deaths were a significant blow to the agency, crippling the team, which is based at Forward Operating Base Chapman and is responsible for collecting information about militant networks in Afghanistan and Pakistan and plotting missions to kill the networks’ top leaders.

The dead came from all corners of the U.S. Several had military backgrounds; one of the fallen CIA employees, a security officer named Scott Roberson, had worked undercover as a narcotics detective in the Atlanta Police Department, according to an obituary, and spent time in Kosovo for the United Nations.

Another, Harold Brown Jr., was a former Army reservist and father of three who had traveled home from Afghanistan briefly in July to help his family move into a new home in northern Virginia.

Brown’s mother, Barbara, said in an interview that her son had intended to spend a year in Afghanistan, returning home in April. He did not particularly relish the work, she said, and talked little about it. “The people there just want to live their lives. They’re normal people,” she recalled him saying.

The base chief, an agency veteran, had traveled to Afghanistan last year as part of the CIA’s effort to augment its ranks in the war zone. After consulting with the CIA, The New York Times is withholding some identifying information about the woman. The agency declined to comment about the identities of any of the employees.

Before the Sept. 11 attacks, the base chief was part of a small cadre of counterterrorism officers focused on the growth of al-Qaida and charged with finding Osama bin Laden.

Working from a small office near CIA headquarters, the group, known inside the agency as Alec Station, became increasingly alarmed in the summer of 2001 that a major strike was coming. One former officer recalls that the woman who led the team had a seemingly encyclopedic knowledge of al-Qaida’s top leadership, and was so familiar with the different permutations of the leaders’ names that she could take fragments of intelligence and build them into a mosaic of Qaida operations.

“Everybody knew what was coming down the pike,” the former officer said. “She was one of the first people in the agency to tackle al-Qaida in a serious way.”

She was not the only veteran Qaida expert killed in the attack. One victim, whose name has not been disclosed, was one of the CIA’s most knowledgeable analysts about the terror network, according to a retired senior agency official.

Two of the dead, Jeremy Wise, 35, a former member of the Navy SEALs from Virginia Beach, Va., and Dane Clark Paresi, 46, of Dupont, Wash., were security officers for Xe Services, the firm formerly known as Blackwater.

The company did not respond to a request for comment about the deaths, but they have been widely reported in local newspapers. The Jeremy Wise Memorial on Facebook had 3,189 fans on Tuesday, filled with recollections of Wise’s childhood growing up as the son of a doctor in Arkansas.

“RIP, Jeremy Wise, American hero,” one wrote.

Afghan blast kills 4 children

KABUL — An explosion tore through a group of children gathered around foreign soldiers visiting a U.S.-funded road project Wednesday, killing four kids and a policeman and wounding scores, including at least three American troops, officials said.

The Afghan Interior Ministry said in a statement that the blast in Nangrahar province in Afghanistan’s east occurred when a passing police vehicle hit a mine.

— The Associated Press