Serhan Gangal and his sister were among a group of tourists waiting for the 8.30pm bus on Tuesday which they expected to shuttle them back from central Venice to their campsite in nearby Marghera. The siblings from Germany, first-time visitors to Venice, had made the 9-mile journey several times during their three-day break, enjoying seeing one of the world’s most famous cities while benefiting from the cheap chalets and swimming pool at the Hu di Marghera campsite. But when the bus, owned by a company hired by the campsite to transport guests to and from Venice, didn’t arrive, a French tourist among the group called the reception desk for information. “He was told that the bus which had left an hour before had fallen off the road and that people had died,” said Gangal. “Everyone started panicking, we felt totally sick – death was literally just one bus away. How could it just fly off the road?” Twenty-one people, including three children, are confirmed to have died when the bus that left Venice an hour earlier crashed through a guardrail and then a railing on an overpass before plummeting 15 metres and bursting into flames next to a train line. Emergency teams worked through the night to extract bodies from the wreckage, which was removed by early Wednesday morning. Flowers were tied to what was left of the crumpled railing and by the train track. Five Ukrainians, a German, and the Italian driver were among the victims. However, confirming the identities of the dead “is complicated”, the Venice prosecutor Bruno Cherchi said during a press conference, and so authorities are referring to DNA samples. Cherchi, who is proceeding with a multiple road homicide investigation into the crash, said only three or four survivors were able to speak at the moment. The injured include four Ukrainians, a German, a Croatian and two Spaniards. Two German brothers, aged seven and 13, who were being treated for broken bones at a hospital in Treviso had lost their parents in the crash, the local newspaper, Il Resto del Carlino, reported. La Nuova Venezia reported that a four-year-old girl taken to hospital in Padua had also lost her parents. The cause of the crash is not yet clear, and a police officer at the scene said the investigation could take months. Luca Zaia, president of the Veneto region, said the main theory is that the driver, who was 40 and had only just begun his shift, may have “fallen ill”. However, others have blamed shoddy road infrastructure. The bus was “brand new, powered by a hybrid” diesel-methane fuel, the director general at Venice city hall, Morris Ceron, said. The vehicle had been travelling slowly and started to skid before crashing into the guardrail, according to initial investigations. The methane is thought to have caused the fire to quickly spread. Domenico Musicco, head of an association for road accident victims, said it was “a tragedy foretold”. “The guardrail was designed for a country road, whereas here we needed new-generation equipment that could have prevented the bus from falling,” he told AFP. “Italian road maintenance is poor. Too little is invested in road safety. It is estimated that 30% of accidents are down to that.” As guests at the Hu di Marghera campsite absorbed the horror of the tragedy on Wednesday, they also contemplated their own fate. “We got the bus that left Venice at 6.30pm,” said Andreea Dumitru, 23, from Romania, who was on holiday with her friend Isabella. “It is very sad and shocking. Our families were frantically calling to check we were safe. We thought to ourselves: ‘God must love us’.” The pair had planned to go back to Venice on their last day, but it didn’t feel right, especially as it would have entailed going past the site of the crash. “People were here on holiday, just like us – how is it something like this could happen?” Sitting by the pool with her friends on Wednesday afternoon, Antonia Moses, 30, who lives in Germany but is originally from Namibia, said they felt too afraid to leave the site. “We are traumatised by what happened,” she said. “We had also considered getting that bus but decided to stay in Venice a little longer. But we didn’t sleep all night as we couldn’t stop thinking about it, and wondering about the victims and how their families must be feeling.”