An eight-year old girl has died with at least 10 people taken to hospital after a car crashed into a primary school in Wimbledon, south London. The Metropolitan police declared a major incident on Thursday morning when a Land Rover ploughed through a fence and collided with a building at the Study private preparatory school for girls aged four to 11. A woman in her 40s has been arrested on suspicion of causing death by dangerous driving and remains in police custody, police said. The incident was not being treated as terrorism-related. Paramedics treated 16 people at the scene, with 10 taken to hospital. Details of their conditions were not immediately released, but it is believed there were at least seven children among the injured. It is thought some of those hurt are in a critical condition. Fifteen ambulances were sent to the scene. The London air ambulance and London fire brigade also attended. TV aerial footage appeared to show the vehicle had crossed a grassed area in the school grounds where it is understood a picnic was being held to celebrate the end of term. The images showed what appeared to be a large mat and a table in the grassed area, as well as substantial damage to one of the school buildings. The Metropolitan police said officers responded to 999 calls at 9.54am. Initially the force said seven children and two adults had been injured. It said in a later statement: “We can now confirm that sadly a child has died following an incident where a car collided with a building at a school in Wimbledon.” DCS Clair Kelland, the local police commander for south-west London, told reporters at the scene: “Very sadly one of the children, an eight-year-old girl, died at the scene. Our thoughts are with her family at this incredibly difficult time.” Her voice breaking, she added: “This is tragic news and our thoughts are with the girl’s family and friends, and everyone affected today. “We remain at the scene and are continuing our investigation into the full circumstances of the incident. “We can also confirm that the driver of the vehicle, a woman aged in her 40s, has been arrested on suspicion of causing death by dangerous driving.” The Wimbledon Conservative MP, Stephen Hammond, whose daughter previously attended the school, said several of those hurt were critically injured. He said: “There are a number of people who are critically injured, as I understand it, and given the scale of the response from emergency services … this is a very serious incident.” Speaking at the scene, Hammond told the PA news agency: “And what a sad incident – it is tragically on the last day of term, for this young girl to have lost her life. “This is a well-liked, well-respected, well-known school. Most of the children who go here will be Wimbledon families, and this will cause shock across the whole of the local community.” He added: “I think it was a usual end-of-year celebration party. Just in the garden. As I understand it, they were inside the school but outside the classroom.” Police extended a large cordon around the school and television pictures from overhead showed the vehicle up against the wall of the building, while firefighters and paramedics stood near a gap in the fencing at the entrance to the site. The school sits on Wimbledon Common, a mile from the All England Lawn Tennis and Croquet Club, which is hosting the world-famous annual tennis tournament. The Royal Wimbledon golf club is nearby. The road on which the school is located has a 20mph speed limit, which is clearly marked with signs and is barely wide enough for two cars to pass each other. In a statement, the school said: “We are profoundly shocked by the tragic accident this morning at Wilberforce House and devastated that it has claimed the life of one of our young pupils, as well as injuring several others.” The welfare of those affected was its top priority, it said. “It is still far too soon to fully understand what happened, but we are well aware of the significant impact this dreadful event will have on our pupils and their families,” it added. One witness, Zac Powell, said: “I saw a lot of distraught parents rushing from the scene on my arrival. Since then I have seen a lot of parents coming and picking up their children with expressions of relief or despair,” he said. The chief paramedic for the London ambulance service, Dr John Martin, told reporters at the scene: “We dispatched multiple resources including specialist critical care paramedics, London’s air ambulance and 15 ambulances. We declared a major incident. We treated 16 patients on scene. Sadly, as we’ve heard, one eight-year-old girl died.” St George’s NHS trust in Tooting, which is about four miles away from the school, told BBC News that staff had received “a number of patients” in connection with the incident, who were being “cared for by our specialist clinical teams”. Downing Street said the prime minister’s thoughts were with the family of the girl who died, and with those injured and involved. “This will have been a terrifying experience for all of the children, staff and parents,” his spokesperson said. The home secretary, Suella Braverman, tweeted she was “saddened to hear about the tragic incident” at the school. The London mayor, Sadiq Khan, described the incident as “absolutely devastating”.