It should have been a banner month for the White Helmets. The acclaimed Syrian volunteer rescue group is the subject of a documentary that was released on Netflix on Sept. 16. The organization is up for the Nobel Peace Prize next month, and a raft of celebrities including George Clooney, Ben Affleck and Justin Timberlake petitioned the prize committee in support of the group’s nomination. On Sept. 22, the White Helmets, who are known inside Syria as the Civil Defense, won the Right Livelihood Award, also known as the “alternative Nobel,” honoring the volunteers for their bravery in rushing to the aid of Syrian civilians under relentless bombardment. The group claims to have rescued some 60,000 people since 2013.

But now, the White Helmets have become the targets of that bombing. In the besieged rebel-held section of the city of Aleppo, at least three of the group’s four operations centers were damaged by airstrikes in one night. Many of their vehicles were destroyed. A fire station was heavily damaged. Even the rescue center featured in the Netflix documentary was destroyed.

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The bombing was the heaviest in months, part of of a new military offensive by the regime of President Bashar al-Assad against the rebel enclave. “Right now people are crying from under the rubble in al-Mashhad, in al-Sukari, in Ansari. We couldn’t respond because we don’t have any vehicles,” says Ammar al-Selmo, a civil defense captain, referring to three eastern Aleppo neighborhoods during a phone interview on Friday. He said two of the four civil defense centers were put out of operation.

Prizes, civic praise, and celebrity backing were not enough to save Aleppo’s first responders, nor its civilian inhabitants. As a part of a new offensive, the Syrian regime and its Russian allies appear to be deliberately targeting the White Helmets, along with other vital infrastructure that sustains the estimated 300,000 people living under siege in rebel-held eastern Aleppo.

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The attacks are part of new, escalating chapter of the civil war in Syria, in which nearly half a million people have been killed since 2011. The current assault on eastern Aleppo began on the night of Sept. 19, when the Assad regime’s military declared an end to a partial ceasefire that went into effect a week earlier under an agreement negotiated by the U.S. and Russia. That night, regime and Russian aircraft resumed heavy bombardment of rebel-held areas, including an attack on a Red Crescent aid convoy in the rebel-held countryside west of Aleppo that killed at least 20 people and destroyed supplies intended to help more than 70,000 people.

The assault on eastern Aleppo has been relentless. Residents described apocalyptic scenes as fighter jets dropped what they described as incendiary munitions and earth-penetrating “bunker buster” bombs that at times caused the earth to shake. Photos and video footage corroborated those witness accounts. At one of the damaged Civil Defense centers, photos taken on Friday showed large vehicles apparently tossed aside by the explosions.

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Other vital civilian infrastructure was also damaged. Attacks on a key pumping station left nearly two million people in Aleppo in both eastern and western Aleppo without running water, according to the United Nations.

“It’s a catastrophe,” says Ahmad Aziz, an aid worker with the Big Heart relief organization in Eastern Aleppo. “Hospitals are full of wounded people and martyrs.”

Overwhelmed medics said they are struggling to cope with a relentless intake of casualties. Eastern Aleppo’s hospitals have already been devastated by a string of attacks by regime and Russian forces. Now, images circulated by medics and activists showed patients lying on a blood-smeared tile floor of a crowded room in one hospital. “The doctors and staff are in exhausted. The work is beyond human capabilities,” says Baraa Omar, a nurse in eastern Aleppo, in a text message. At least 23 people were killed on Sunday alone, according to activists quoted by The Associated Press.

The U.S. excoriated Russia at an emergency meeting of the U.N. Security Council held on Sunday in New York. “She said: “Instead of peace, Russia and Assad make war,” said Samantha Power, the US. ambassador to the U.N. Instead of getting life-saving aid to Syrians, Russia and Assad are bombing hospitals and first responders.” Vitaly Churkin, Russia’s ambassador to the U.N., said that Russian forces were not involved, and blamed opposition armed groups of disrupting the cease-fire.

The Assad regime appears determined to invade and possibly retake the rebel-controlled section of Aleppo, which is among the most important areas held by the armed opposition groups that emerged following a peaceful uprising in 2011. The recapture of Aleppo would constitute a body blow to the armed rebellion, which has maintained its grip on a portion of the city against overwhelming odds. The city used to be Syria’s largest by population and the heart of its economy. It remains central to any plans by the regime to survive even though it has lost huge portions of the country to the rebels, Kurdish armed groups, and jihadist militants such as ISIS. Any sustained attempt by the regime to retake the eastern part of the city is expected to be slow and extremely bloody.

The current onslaught on eastern Aleppo also signals the collapse of recent U.S. diplomacy on the Syrian conflict, which sought to deescalate the conflict in cooperation with Russia. The truce agreement that unraveled last week called on Russia to restrain its ally, the Assad regime, from pursuing indiscriminate attacks on civilians in the rebel-held areas. After a week in which the cessation of hostilities was battered by continued regime attacks (and one mistaken international airstrike that killed regime soldiers), the pro-Assad forces and Russia did the opposite, launching one of the most intense and sustained assaults in the five-year span of the conflict.

On the ground, medics and rescue workers continue to rush to the aid of other civilians. On Friday, the day after airstrikes knocked out two of Aleppo’s four civil defense centers, volunteers continued to pull victims from the rubble of destroyed buildings, including children. “That’s the situation right now. I don’t know what happens tomorrow. We still work, until death. We have no choice.”

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