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Danya Bacchus reports from the fire that damaged a McDonald's in the 1200 block of Encinitas Boulevard on Thursday, Sept. 2, 2011.
An explosion rocked a North County McDonald's with employees and customers inside.
Fire investigators have not revealed what caused the explosion at the restaurant on Encinitas Boulevard around 8:30 p.m. Thursday.
Customer Jeff Pinkerton said he was one of about four or five customers in the restaurant's eating area when it sounded like a bomb went off.
"We turned around and all of a sudden flames started coming from behind the stoves," he said.
"Everybody was saying get out. Everybody just ran - I mean, fast," he said.
"It just went up real fast."
Firefighters responded but they had to stay back because a lot of the roof was already gone by the time they had arrived and it wasn't safe for them to go inside.
The fire blew through the roof on the back side of the restaurant according to Robert Scott, Fire Marshal and Fire Investigator.
Scott didn’t want to speculate just yet on the cause.
The outside walls will likely remain standing he estimated. There may be heat, water or smoke damage to nearby businesses.
Forty firefighters from Carlsbad, San Marcos, Rancho Santa Fe and Encinitas fought the fire.
No one was injured.
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