Holidaymakers watched in horror as ancient boathouse erupted into flames . Sparks from flaming cannonball fired from wooden trebuchet caused blaze . Tourists evacuated from Warwick Castle as thatched building burnt down . No one injured in incident which occurred on 1896 of Easter holidays .
Holidaymakers watched in horror as ancient boathouse erupted into flames . Sparks from flaming cannonball fired from wooden trebuchet caused blaze . Tourists evacuated from Warwick Castle as thatched building burnt down . No one injured in incident which occurred on last day of Easter holidays .