KABUL, Afghanistan — The teenage students were lowered into a mass grave one after another, shoulder to shoulder — just as they had sat at their lecture hall the day before.
A suicide bomber, perhaps no older than they, had walked in as their algebra class ended and physics was about to begin, detonating his explosive vest and turning the university prep center into a scene of carnage.
On the whiteboard, basic algebraic equations were covered in blood. A nearby blackboard, where “Valentine day” was written in faded chalk, was riddled with holes from the ball bearings that were packed into the bomber’s vest.
The lecture hall had been so packed, and the explosion so powerful that more than a third of the 230 students were among the casualties. Health officials said more than 30 were killed and dozens were wounded. The mangled bodies were hard to identify.
At the hilltop burial site on Thursday, Roshan Ghaznavi, a human rights campaigner, wept over the coffin of a girl named Negina from a poor family; she had been their best hope for a better life.
“Today, it is Negina’s casket, tomorrow it will be my casket, the day after it will be your casket,” Ms. Ghaznavi said. “Humanity is dead here. It’s been dead for a long time.”
The attack was claimed by the Islamic State, its latest in a brutal string of bloody bombings against civilian targets, everything from mosques to schools, and even a midwife training center. The Islamic State’s hold on Afghan territory was never large, and has been slipping, but its cruel brand of bloodshed has compounded Afghans’ suffering during years of war against the Taliban.
The Kabul school’s casualties were just a small fraction of the relentless bloodletting by a resurgent Taliban in the past week, when attacks took the lives of several hundred Afghans, security personnel and civilians.
Most of the students at the education center, called Mawoud Academy, had moved from villages in central Afghanistan to spend a year in Kabul preparing for the country’s competitive university entrance exam. Their families had saved so the children, staying in $ 15-a-month hostels in Kabul, could pursue a universal dream: a good education as their ticket out of poverty and isolation.
For the families, the choice to send their children to the capital has become increasingly fraught. Seventeen years after the American invasion, foreign money still powers opportunities for advancement in the city. But the recent wave of violence has made the cost of those opportunities a heavy one.
Many of the dead from the school were transported back to their villages. But about a dozen, like Negina, were brought to the hilltop in the west of Kabul, close to another mass grave for the victims of an Islamic State bombing two years ago. An excavator did the initial digging, before local men — some in suits, their jackets neatly folded in the dirt — dug with shovels and pickaxes.
Some of the caskets were carried by fellow students or relatives who had made it to the burial. Others were shouldered by volunteers who had heard the news and arrived to help.
“Nobody knows where he was from,” said Haji Abas, who was sitting next to a coffin marked Azizullah.
“He has no one here, no family,” someone said.
“We are his family,” Mr. Abas said. “Let’s move him closer to the others.”
Among the first to be buried were twins, Attaullah and Farzana, 19.
They were the first children of their parents, born and raised in Ghazni Province before their family moved to Kabul nine years ago. Their mother was a seamstress; she would often sew them matching clothes when they were babies, their cousin Abdul Qader Rahimi said.
“Attaullah was the first to be born, and he grew faster than Farzana,” Mr. Rahimi said. “She would tease him that he drank her share of milk, that’s why.”
“One could not live without the other — that is why they left the world together,” Mr. Rahimi said. “They were one soul, in two bodies.”
Then there was Negina. No one at the cemetery really knew much about her.
Her only friend helped other women inch the coffin closer to the grave until its turn arrived. Then she fainted. Other women unbuckled her shoes and splashed her face with water.
Later, a university lecturer who had rented Negina a room filled in some of the blanks about her life. Two weeks ago, he said, a woman from Jaghori district, in restive Ghazni, had arrived in Kabul with a toddler and a high school graduate, Negina. The woman said her husband was ill, and her son was working as a laborer in Iran. She wished for Negina to enter university, and then get a well-paying job to lift the family.
Ali Farhang, the lecturer, said Negina and a roommate split the monthly rent for one room: $ 30.
He said Negina and her roommate had waved goodbye to him on their way to class around 2:20 p.m. The explosion hit at 3:45.
“I peaked into their empty room from the window last evening,” Mr. Farhang said. “Their lunch bowl was still there — just a salad of tomatoes and onions.”
The academy, down a narrow lane, remained closed on Thursday, except to the relatives who came to pick up the dozens of handbags and backpacks left behind. The roof was blown off. The chairs, covered in blood, were piled in corners.
Police officers guarding the premises sat in the dirt behind the walls, having their lunch of bread and potato curry.
“Gather your strength so you don’t cry,” one of the officers said, as reporters went inside. “We cried a lot.”
Masuma, wearing a checkered shawl, came searching for the handbag her daughter, Atika, had left behind. Atika had been in the next-door classroom and had survived. Her bag held four books and four pens, Masuma said.
“There are a lot of bags like that — dozens,” the guard answered, as he led her to rows of tables piled with bags. The contents had been pulled out so relatives could more easily identify their children’s belongings.
As they searched, the guard asked how her daughter was doing.
“She is not normal,” Ms. Masuma said. “When she sees the photos, she cries a lot.”
They found the bag in the lecture hall where she had been seated.
“Yes, this is hers,” Ms. Masuma said. “It has four books and four pens.”
For some, the end of their search was sadder still.
Hamid Omer had spent much of the evening of the bombing going hospital to hospital to find his sister Rahilla, 17. The night before, they had talked about a potential wife for him. In the morning she ironed his work pants before heading to class.
He finally found her at the government morgue.
“There were two bodies: a boy and a girl.” Mr. Omer said. “I was numb, but I had to check the girl. When I checked, her head was shattered, not recognizable.”
Then he noticed a watch he thought was his sister’s. He called home, somehow hoping that someone else had the same watch and hers would be there. It was not.