A fire broke out on an exterior set of Hogwarts School of Witchcraft and Wizardry at Leavesden Studios outside London Friday night, but early reports of the size of the fire and the resulting damage have been exaggerated, according to a source familiar with the incident. During filming for a scene in the final Harry Potter installment, Harry Potter and the Deathly Hallows, a small fire ignited and was quickly extinguished. No actors were present at the time, no one was injured, and no significant damage was caused to the set or to the studio lot in Watford, where all of the Potter movies have been filmed. A fire truck was called to the studio as a precaution, but the fire was out by the time firefighters arrived. The studio, Warner Bros., declined to comment. Hallows, the final book of the Potter series, is being made into two films. The first will be released this fall, on Nov. 19. The second will be released next summer, on July 15, 2011. So far the franchise has grossed more than $5.4 billion worldwide.