Vika Kallagova could have run away. When Chechen terrorists stormed Beslan School No. 1 on Wednesday, Sept. 1 — her 13th birthday — she was well placed to escape. She and a group of other older kids were standing at the far end of the crowd of over 1,200 children, parents and teachers assembled to celebrate the first day of the new school year. So when the shooting started she and others made a break for the school's ramshackle heating plant. The 30 or so attackers did not chase them: they were too busy herding their hostages into the school gymnasium. The children crouched in the heating plant began to scramble to safety. Some of them got away. But Vika suddenly realized that her sister Olya, 7, was not with her, so she stayed. When 10 or so gunmen started rooting around the area, calling for people to come out, she did so. They pushed her back into the school. "I couldn't leave," she said later. "Olya was there."

Sept. 1 was Vika's first birthday without her mother, Lena, who died in childbirth last February. "Vika almost died on the first of September 13 years ago," says her father, Taymuraz. "Her mother had a very difficult delivery." After Lena's death, Taymuraz and his mother — more or less 93 years old, no one remembers — took over the role of mother in their small, pleasant house on Komintern Street, about a mile from the school. "It used to be a very quiet place to live," says Akhmet, a neighbor.

Then came the siege. For the entire first day, Vika could not find Olya amid the mass of humanity packing the gymnasium floor. The gunmen strung bombs from the ceiling beams and basketball hoops, and warned everyone not to move. But Vika pretended she wanted to go to the toilet and made her way across the length of the gym, looking for her sister. Olya's homeroom teacher Emma Karyaeva saw her and waved. Vika slipped in next to them. Vika's own homeroom teacher, Albina Alikova, was with them. Olya was asleep. "Olya slept a lot," says Vika in the faintly disapproving voice of an older sister. She is tiny and did not need much space. "But I couldn't even lie down," she recalls.

When the first bomb went off on Friday — it seemed to just fall off a basketball hoop, Vika says — Karyaeva threw herself over Olya to cover her from the blast. When Karyaeva got up after the blast the girls saw she was covered in blood. They urged her to run, but she stumbled against Vika. "Save yourselves," Karyaeva said. She and her small daughter both died. So did Vika's teacher Alikova. Sometime during the explosions the two sisters were injured: Vika in the leg, Olya in the arm. Two gunmen pushed them and a crowd of others down a corridor where a firefight was already under way, and into the cafeteria. Vika sheltered her little sister. "We were there two hours, if not more," she says. The girls' memories are mercifully fragmentary: the cafeteria was the scene of horrific carnage as guerrillas were torn to pieces by gunfire and explosions. Vika led Olya through the cafeteria and into the small kitchen. "I hid in one cupboard and I shoved Olya into another," she says. They were eventually pulled to safety by Russian special forces. They spent three weeks in the same hospital where their mother had died, and came home Sept. 27. By then perhaps 30 people from their street had been buried; their father, who works for the water company, lent out the company excavator to dig their graves. On the first evening home Vika watched a local TV listing of those still missing, names and photographs scrolling down the screen. She cried all night. Olya refuses to look at TV pictures of the school. The scars run deep, but two girls are alive. A big sister refused to leave her little sister behind. Amid so much senseless death, that is something to hold onto.