16th century prep school gutted by fire The school has already finished for holidays but it is thought some 25 pupils may have been staying there at the time. The area was evacuated and nobody was injured. Deputy headteacher Chris Townsend said: "We have already broken up for the summer. " Firefighters battled the inferno for nearly five hours but were hampered in their efforts by a lack of water despite years of planning targeted at a 'worst case scenario' blaze at the school building. Major building works took place for the 400th anniversary celebrations in 1964, when the Queen Mother laid the foundation stone for the then new Music School. A full-scale training exercise just over 18 months ago saw 45 firefighters and nine appliances descend on the school to practice a pre-organised routine. At the time fire bosses said the exercise - which took a year and a half to organise - had gone off without a hitch. Deputy headteacher Chris Townsend said at the time: "This kind of exercise is crucial to make sure we understand our procedures and the fire service understand our building. School House is the biggest and oldest building making it the most difficult to evacuate and to tackle a fire within it if one were to ever break out. At any one time there could be 60 students sleeping in there and by doing this we are giving them the best chance of survival in the result of a fire. Today the boarding school confirmed that none of its pupils had been staying there at the time of the blaze but that 25 students from Stafford House International Summer School were in residence when the fire began and had been evacuated safely. No one has been reported injured. Firefighters eventually contained the blaze just before midnight after being forced to pump water from a lake half a mile away due to problems with a lack of water supply. Crews remained at the scene this morning damping down hot spots as structural engineers were called in to begin to assess the damage caused by the huge blaze. Ray Skinner, Essex County Fire and Rescue Service Divisional Officer, said: "We have been hampered throughout this incident by a poor water supply. We are using the high volume pump to get water from a lake around half a mile away. Crews will be here throughout the night working to contain the fire and this will supply the many gallons of water they will need. Firefighters have been working extremely hard in difficult conditions. On arrival crews were faced with a large and well established fire which has spread inside the building which is now completely alight. We now have the fire contained but crews will remain here throughout the night continuing to contain the fire and make sure that it does not spread to the nearby house. There is still a great deal of work for us to do here. A full investigation has been launched to uncover the cause of the fire. The Princess Royal opened the new Lord Riche Hall in 1989. Girls were taken into the Sixth Form in 1970, and into the whole school in 1993.