Officials said the courthouse square and the clocktower that enabled Michael J Fox's character to time travel in Back to the Future
Sets from other classic films such as The Sting
, The War of the Worlds
were also damaged. The set from the current hit television series Desperate Housewives
Daryl Jacobs, the Los Angeles county fire inspector, said at least one building had burned and as many as three blocks of film facades were destroyed.
"The facades are constructed of heavy timber and they tend to burn quite freely," he said.
For a time, firefighting helicopters swept in to drop water.
Reynoso said there had been at least one explosion.
The video vault contained tens of thousands of videos and movie reels before it was destroyed, but Ron Meyer, Universal Studios chief executive, said its main archive did not suffer irreversible losses.
"The video library was affected and damaged, but our main vault with the motions pictures negatives was not," he said.
"Nothing irreplaceable is lost... We were very lucky. It's a bad situation, but it could have been a lot worse."