Authorities are hunting for clues behind Monday's bombings at the Boston Marathon that killed three people and injured 176. According to The Boston Globe, 70 victims remained in Boston hospitals Tuesday night, including 24 in critical condition. FBI officials say the two bombs were probably built in six-liter pressure cookers filled with nails and small ball bearings. The bombs were then hidden in bags left on the ground. Meanwhile, more information is coming out about the victims: eight-year-old Martin Richard, who was seen in a photo holding a sign that read, "No more hurting people. Peace."; 29-year-old Krystle Campbell, a restaurant worker; and Lu Lingzi, a Chinese national attending graduate school at Boston University.

Boston Marathon Bombing Hospitals