On Tuesday, giggling children shouted, clapped and sang beside swings and a slide in the courtyard of al-Ahli Arab hospital in Gaza, captured on video as medical staff tried to distract them from airstrikes pounding their city. The next morning, just a few metres away, a grim faced man climbed on to a shattered roof to retrieve the lacerated remains of a tiny infant, one of the youngest victims of a devastating blast that turned a place of healing into a slaughterhouse. The explosion ripped through a courtyard and car park filled with refugees early on Tuesday evening. The crowd had come to the church-run hospital seeking refuge, and spent the afternoon singing peace songs to keep up their spirits, said Hosam Naoum, the Anglican bishop of Jerusalem, who overseas al-Ahli. They knew it was a place of only relative safety. Israeli forces had ordered the directors of al-Ahli to evacuate the hospital three times over the previous four days, reaching them by phone on Saturday, Sunday and Monday. Two missiles also hit a hospital building on Saturday, Naoum said. Administrators shared news of these warnings, and thousands left, but as bombing intensified in surrounding neighbourhoods, they flooded back. “We had a moral obligation … We told them it is important you know what is taking place, but they have nowhere to go,” Naoum said. “At that point in time [of the blast], we know there were thousands of people there.” “There was some bombing and airstrikes around the hospital and they fled in.” That flow of people in and out of the compound, as they tried to make impossible decisions about where might be safe in a city under relentless attack, had been “happening all the time, back and forth” he added. For hundreds, the gamble on al-Ahli on Tuesday would prove fatal. The refugees bore the brunt of the blast, with medics and patients protected by hospital walls. Naoum said two employees were injured. Israel has denied hitting the hospital, saying that the blast was caused by the warhead and propellant of a misfired Islamic Jihad rocket. The White House said its current intelligence assessment also showed Israel was “not responsible” for the explosion, but information was still being collected. Naoum declined to attribute responsibility for the blast, saying that priests were not military investigators, but he condemned the Israeli bombing campaign and called for a ceasefire. Footage of the explosion filmed from a Gaza city balcony captured a whistling overhead, the thump of a giant blast, then a fireball lighting up the dark sky. As a cloud of smoke billowed into the sky, lit red by flames below it, survivors on the ground blinked through the dust and smoke at a scene of horror and tragedy, animated by screams of the injured. At least 471 people were killed and more than 300 injured, according to Gaza officials; bodies lay on the ground between scattered belongings and burnt-out cars. Many victims were torn apart or thrown across the hospital in the explosion. “In between cases I heard the screech of two missiles and then a loud explosion,” said Ghassan Abu Sittah, a British-Palestinian surgeon who was inside the hospital at the time. “As I walked towards the side entrance of the operating room, I saw that the hospital itself was on fire and that it was directly hit. The wounded started stumbling towards us,” he wrote in a post about the night of horror. “I put a tourniquet on the thigh of a man who had his leg blown off, and then went to tend to a man with a penetrating neck injury.” Social media images from the hospital compound showed people with gruesome injuries, and medics racing to get them from the hospital where they were injured, to one where they could be treated. Ambulances and private cars transferred 350 people to the city’s biggest hospital, Dar al-Shifa, its director, Mohammed Abu Selmia, told the Associated Press. Already overwhelmed by patients injured in days of airstrikes, the hospital’s doctors were reduced to attempting surgery on the floor and in the halls, mostly without anaesthesia. “We need equipment, we need medicine, we need beds, we need anaesthesia, we need everything,” Abu Selmia said, of a hospital now even more stretched, warning that fuel for the generators would run out within hours. After those who could be saved were getting treatment, and most of the dead had been recovered, doctors and health officials held a bleak press conference surrounded by body bags. The scale of the horror echoed around the world, sparking protests and prompting Jordan to cancel a planned summit with the US president, Joe Biden, and Palestinian and Egyptian leaders. The morning after the blast, abandoned bedding was scattered in the hospital chapel under shattered windows. Ashes still smouldered under charred palm trees, beside children’s backpacks and jumbled possessions: clothes, shoes, a stereo, some now smeared with blood. Despite the damage, the hospital has already reopened to serve the people clinging on in the wreckage of Gaza City. Solar panels mean it has electricity and water, and the need for medical help is urgent. Israel ordered a complete civilian evacuation to the south of Gaza, but many were unable to travel and some chose to stay: civilian convoys have been hit heading south, there are airstrikes in southern Gaza too, and shelters and most private homes are already full of refugees. Stunned survivors surveyed the damage early on Wednesday morning and collected papers and belongings that had survived the devastation. With rolls of bedding on their backs, they set off into a city where now, more than ever, they know there is no safe place for civilians.