Fire fighters examine the scene on the fire damaged lot of Universal Studios today (AP Photo/Nick Ut)

The gates of Universal Studios opened back up today after yesterday's fire, which burned a two-block area of film sets for more than 12 hours. The incident forced them to close the doors for the day at the theme park and CityWalk. Areas destroyed or damaged included New York Street, a part of Back to the Future's set and the King Kong attraction.

"A preliminary investigation determined the fire was an accident, said Los Angeles County fire Capt. Mike Brown. He would not provide further details, but county officials planned a Monday afternoon press conference," reported KCBS at 4:23 p.m.

Plastic burned in the Video Vault, sending toxins into the air along with the large plume of smoke that some residents took for movie special affects before realizing it was a real fire. There were concerns about the health risk of breathing the tainted air the surrounding neighborhoods, but today preliminary results show that the effected air contained toxins that were "six times or more above normal," but were still under levels that would be considered a health risk.

The tapes that burned were unrecoverable but Unversal Studios officials said they were copies and replaceable. Rumors surfaced that original music archives were lost, but that was retracted by music representatives earlier today.

The fire began early Sunday morning around 4:45 a.m. and lasted through out the day, shutting down the theme park and injuring 10 people, but did not force the cancellation of the MTV Movie Awards. See photos from the fire here.