On Aug. 7, 1998, U.S. Embassies in Dar es Salaam and Nairobi, Kenya, were bombed by trucks filled with 17 tons of explosive devices, killing 223 and injuring more than 4,000. Twelve of the dead were Americans.
At the Embassy Bombing Memorial, the two first ladies placed flowers at the foot of the memorial and paused for a moment of silence Monday.
After the commemoration, the first ladies went to an auditorium where the Baba wa Watoto dance performed for the first ladies and Obama's daughters, Sasha and Malia.
Tanzania is the final Mrs. Obama's final leg in a three-nation tour of Africa. In Senegal, she spoke to middle-school girls about success. While in South Africa, Obama conducted an online chat with South African teens and American students.
After participating in the African First Ladies Summit Tuesday with former U.S. first lady Laura Bush, Obama will return to the United States.