The men awoke in the middle of the night to the roar of warplanes.

Fear was nothing new to Fanta Ali Ahmed, who was trapped with more than 100 migrants in a rickety prison. After civil war reached his home region of Tigray in Ethiopia in 2020, he had fled along one of the world’s most dangerous smuggling routes.

He had hoped to reach Saudi Arabia, across the Red Sea. Instead, as he passed through Yemeni territory ruled by the Houthi militia, he was arrested and sent to a migrant detention center in northern Yemen.

For weeks in March and April of this year, he heard American airstrikes nearby, targeting Yemen in a campaign against the Houthis, who are backed by Iran. But this was the closest the planes had ever come.

When multiple 250-pound bombs hit the prison on April 28, tearing through the roof, Mr. Fanta fell to the ground, he recalled. At first, he thought he was the only one hurt. He later realized that he was one of the luckier ones. Ten people close to him were killed, while others were left with limbs hanging by shredded skin, he said.

“The place and everyone in it were mangled,” said Mr. Fanta, 32, who survived with two broken legs and a broken arm. “I don’t know why America bombed us.”

More than two months after the attack, which killed at least 60 people and injured 65 more, according to health authorities in the Houthi-led government, few answers have emerged. The Houthis blamed the United States, and an investigation by The New York Times found that at least three U.S.-made GBU-39 bombs — relatively small, guided munitions that are typically intended to reduce collateral damage — had been used, suggesting that the United States was likely to have carried out the bombing.

U.S. Central Command, which oversees military operations in the region, has not claimed responsibility, saying only that officials were “aware of the claims of civilian casualties related to the U.S. strikes in Yemen” and were conducting an inquiry.

A reporter for The Times visited survivors of the strike and what remained of the prison in May. In order to gain access to the restricted sites, he was escorted by an official from the Houthi-led government. The Houthi authorities did not impose restrictions on The Times’s coverage or review it before publication.

To the men who survived the attack, there was little doubt who was behind it.

“What are we supposed to say to America?” Mr. Fanta said, his body shaking with laughter as he lay on a hospital bed in the Yemeni city of Saada. “Can I respond to America? Threaten America, for example?”

Binyam Aksa, 26, a day laborer from Tigray whose leg was broken in the bombing, said he could not fathom why they had been struck.

“I just want to know why we were targeted,” he said. “What did we do to them to be punished like this?”

The road to Saada from the Yemeni capital, Sana, is filled with groups of African migrants. From Saada — in the northernmost region of Yemen, a Houthi stronghold — it takes about a day to walk to the border of Saudi Arabia, their destination.

On a recent afternoon, a Times reporter saw a red truck halt just before a security checkpoint. Dozens of migrants climbed out, scattering across the roadside as they tried to avoid detection.

A few months ago, Mr. Fanta was in their place. In Tigray, he had worked as a farmer and sometimes a guard. “War was breaking out everywhere,” he said, so he decided to head for Saudi Arabia, leaving behind his wife and two children. He wanted to find a job on a farm or herding sheep.

He rode a smugglers’ boat across the strait separating Africa from the Arabian Peninsula. From the southern Yemeni city of Aden, he made a long trek north on foot, pushing through hunger and thirst to reach the Saudi border, he said.

This journey, called the Eastern Route, is one of the “busiest and riskiest migration routes in the world,” according to the International Organization for Migration. Tens of thousands of people attempted the trip last year, fleeing conflict, poverty, drought and political repression in countries including Ethiopia, Eritrea and Somalia.

To reach Saudi Arabia — where they hope to disappear into a vast informal economy — they must first traverse Yemen.

Yemen has been torn apart by its own war since 2014, when the Houthis ousted the internationally recognized government from Sana. A Saudi-led military coalition — backed by American military assistance and weaponry — embarked on a bombing campaign to rout the militia from power. Hundreds of thousands of people died from violence, disease and starvation. The coalition eventually pulled back, leaving the Houthis entrenched in power in northwestern Yemen, where they rule with an iron fist.

Mr. Fanta’s journey was stalled when Saudi border guards shot at migrants trying to cross, he said. Border guards in Saudi Arabia regularly open fire on migrants trying to cross from Houthi territory, according to Human Rights Watch and doctors at hospitals nearby. The Saudi government has dismissed those allegations as unfounded.

Then, before Mr. Fanta was able to cross, he was arrested for consuming alcohol, he said. In prison, the migrants heard airstrikes nearby and nervously watched television broadcasts about the American bombing campaign, he said.

When the U.S. strikes started in 2024, under President Joseph R. Biden Jr., officials said their goal was to deter the Houthis from firing missiles and drones at Israel and attacking ships in the Red Sea. Houthi leaders say their operations are an attempt to pressure Israel to stop bombarding Gaza and increase the flow of humanitarian aid.

The Trump administration began its own bombing campaign in March.

The Pentagon said it had struck more than 1,000 targets in Yemen, destroying “multiple command-and-control facilities, air defense systems, advanced weapons manufacturing facilities, and advanced weapons storage locations.” It is unclear why the prison might have been a target. Officials have been opaque about individual strikes. In a statement on April 27, Central Command said that, to preserve operational security, it “will not reveal specifics about what we’ve done or what we will do.”

One day later, the prison was struck. More than 100 Ethiopian migrants and one Eritrean migrant were inside, said Maj. Ahmed Ali al-Kharasi, the prison director.

The detainees were accused of a variety of criminal offenses, like hashish smuggling, alcohol consumption and murder, and were meant to serve their sentences before deportation, he said.

“Everyone knows this place has been a prison since 2019,” he said. “Why are they being targeted?”

Outside what remained of the prison, on white tarps, local authorities laid out shards of the bombs that had struck the facility.

The building had collapsed during the attack, scattering twisted metal and cinder blocks amid scraps of the migrants’ lives: plastic bottles, abandoned shoes, a crumpled pair of jeans.

The site was once a military barracks. In 2022, it was targeted by the Saudi-led coalition with airstrikes that killed dozens of people, and Saudi officials said that the location was a Houthi “special security camp.”

When United Nations representatives visited the site in January 2022, they “saw no signs” that it still served a military function, Rupert Colville, a spokesman for the U.N. high commissioner for human rights, said at the time.

The International Committee of the Red Cross, an aid organization, had just visited the prison a few days before the recent attack, Major al-Kharasi said.

Mr. Binyam, the day laborer from Tigray, said that 20 of his friends had been killed, and that many had been injured.

“Some had their hands amputated, others lost their arms,” he said. “Some had their faces disfigured, others lost their eyes.”

Birhane Kassa Kahsay, from Tigray, described realizing that the walls had fallen, and that he was underneath.

“I was dug out from the ruins and brought here,” he said.

Survivors began arriving at the Republican Hospital in Saada around 4 a.m., said Mujahed Ahmed Shawqi, a doctor at the hospital. More than 40 men had critical injuries, including spinal fractures and chest trauma, he said.

“I couldn’t sleep for two consecutive days from the horror of the scene,” he said.

Amnesty International has called for an independent investigation into the attack.

“The major loss of civilian life in this attack raises serious concerns about whether the U.S. complied with its obligations under international humanitarian law,” Agnès Callamard, Amnesty International’s secretary general, said in a statement.

Israel also has GBU-39s. The Israeli military, responding to a request for comment from The Times, said that it did not strike Yemen at all in April.

The American airstrikes in Yemen have halted — President Trump declared an abrupt cease-fire on May 6. Israeli attacks in Yemen continue, as do Houthi attacks in Israel. Last week, the Houthis also resumed attacks on ships in the Red Sea, which Mr. Trump had said the truce would halt.

As he waited to recover, Mr. Fanta said he did not know where he would go. He might stay in Yemen or return to Ethiopia. But he will not resort to paying smugglers to reach Saudi Arabia again, he said.

“I’m fleeing death in the first place,” he said, “only to find death waiting for me here.”

Tiksa Negeri contributed translation assistance from Addis Ababa, Ethiopia. Johnatan Reiss contributed reporting from Tel Aviv.