Over 70 schoolchildren were left screaming in terror after the top deck of the bus they were travelling in was completely sliced off when it slammed into a low  bridge. The youngsters, who were on a school trip to the Thorpe Park amusement park, were forced to duck for cover as the vehicle hit the railway bridge in Staines, Surrey, shortly after 10.20am. Miraculously nobody was seriously hurt in the crash although 11 people have reportedly been taken to hospital to be treated for minor injuries. Scroll down for video . Lucky escape: The roof of this double decker bus, which was reportedly carrying 76 schoolchildren, was completely ripped off after it hit a low railway bridge . There are understood to have been 76 schoolchildren aged 14 or 15 as well as four to five teachers from  St John's School in Epping, Essex, were on board at the time. Writing on the school website, headteacher George Yerosimou said: 'I have just been informed that the double decker coach transporting our students on the Gold Trip to Thorpe Park has been involved in an accident. 'We have spoken to a number of staff and we are able to confirm that there are no serious injuries although some students may have suffered some cuts and bruises.' Wreckage: The roof of the bus lies on the road next to the railway bridge following the accident in Staines, Surrey . Passengers: In total 76 schoolchildren and four or five teachers from St John's School in Epping, Essex, were on board the bus when the accident happened . The school's website says pupils are given the opportunity to go on a reward trip if they achieve a high number of house points. Christopher Nice, a spokesman for Galleon Travel, said: 'A double-decker bus picked up 76 children from St John's School in Epping at 8.30am. 'They were on their way to Thorpe Park. On one of the roads in, the bus struck a bridge. 'Fortunately, as far as we are aware, none of those passengers on the bus have sustained any serious injuries. 'As of 11am, Galleon Travel were in the process of arranging for a replacement vehicle to take them back to the school.' Emergency services rushed to Chertsey Lane in Staines after the crash while eyewitnesses reported seeing the roof sliced free from the vehicle . Headteacher George Yerosimou said no one had been seriously hurt in the crash although 11 people have been taken to hospital with minor injuries . Emergency services rushed to Chertsey Lane in Staines after the crash while eyewitnesses reported seeing the roof sliced free from the vehicle . Emergency services rushed to Chertsey Lane in Staines after the crash while eyewitnesses reported seeing the roof sliced free from the vehicle. A man travelling on a train said: 'I saw some young girls pointing at the bridge then all debris was flying in the air. We were directly overhead when it hit.' Another said: 'A double-decker bus tried to go under a low bridge, there were children on board. 'How nobody has been killed is unbelievable. The bridge is now blocked by the roof. According to the school's headmaster, 11 people were taken to hospital with minor injuries . Val Mitchell, a receptionist at Staines and Thameside Medical Centre in Chertsey Lane, said: 'The doctors have been out to help. There have been no major injuries but a couple of the youngsters suffered minor injuries. 'It involves a coach full of school children from Essex. They are of secondary school age, around mid teens, roughly 14 or 15. 'The driver tried to go under the bridge and it took the roof right off. The roof was completely ripped off. 'They obviously managed to duck at the right time. It is quite a miracle that they did not suffer any major head injuries. 'One of the youngsters had glass in his head and a few had minor cuts. Two or three have been taken to hospital as a precaution. 'Thankfully there were no serious injuries but they are very shaken.' South East Coast Ambulance Service declared it as a 'major incident' after the call came in at 10.16am, with a number of ambulances from Surrey and London sent to Chertsey Lane, which is expected to be shut for hours. A total of 58 walking wounded were reported, and 10 people were assessed at the scene. Three were taken to St Peter's Hospital in Chertsey to be treated. Ambulance spokesman Justin Wand said: 'We have robust plans in place for managing incidents of this nature and will be working with our emergency service partners to ensure that we assess and treat anyone who may be injured as swiftly as possible.' The vehicle was operated by Galleon Travel. A spokesman said: 'They left school at 8.30am and we know that the bus struck a bridge at the entrance to Thorpe Park. 'Emergency services were at the scene shortly afterwards. As far as we are concerned there weren't any serious injuries to the passengers inside the vehicle. 'The company were in the process of arranging to take the passengers back to school, I do not think they have gone back to Thorpe Park.' The schoolchildren were on a trip to the Thorpe Park amusement park in Surrey as a reward for good work . A spokesman for Surrey Police said: 'Officers are working closely with the South East Coast Ambulance Service and Surrey Fire and Rescue Service at the scene. 'Police have closed Chertsey Lane at the junction with Riverside Drive and at the Chertsey Lane roundabout while the emergency services deal with the incident. 'The road is expected to remain closed for a significant period and motorists are being advised to avoid the area if possible. '
Youngsters forced to duck for cover as bus slammed into the bridge . They were being treated to a trip to Thorpe Park as a reward for good work . Eyewitnesses report seeing the roof being sliced free from the vehicle . Miraculously nobody was seriously hurt although 11 people were taken to hospital with minor injuries .