A young U.S. diplomat killed in an attack in southern Afghanistan was an up-and-comer in the State Department and loved working directly with residents of the country, those who knew her said Sunday.

Anne Smedinghoff, a 25-year-old foreign service officer, died Saturday when the group she was traveling with was struck by an explosion in southern Zabul province. They were traveling to donate textbooks to students. An employee with the U.S. State Department and three U.S. soldiers were also killed in the attack.

The Chicago-area woman is the first American diplomat to die on the job since last year's attack on the U.S. diplomatic installation in Benghazi, Libya.

Secretary of State John Kerry said Sunday at a news conference in Turkey that Smedinghoff was "vivacious, smart" and "capable." Smedinghoff had assisted Kerry during a visit to Afghanistan two weeks ago.

Kerry also described Smedinghoff as "a selfless, idealistic woman who woke up yesterday morning and set out to bring textbooks to school children, to bring them knowledge."

Anne Smedinghoff's parents said in an emailed statement to The Washington Post that their daughter joined the foreign service straight out of college.

Tom and Mary Beth Smedinghoff also said their daughter died doing what she loved.

"Working as a public diplomacy officer, she particularly enjoyed the opportunity to work directly with the Afghan people and was always looking for opportunities to reach out and help to make a difference in the lives of those living in a country ravaged by war," they said.

Smedinghoff previously served in Venezuela.