RANCHO CORDOVA (CBS13) – The fire that damaged several cars at an auto auction yard in Sacramento County early Monday morning was not arson, says an investigator.

The flames were first reported around 3:30 a.m. in a car lot behind Insurance Auto Auctions Inc. on Douglas Road near Sunrise Boulevard. Firefighters from Sacramento Metro Fire arrived at the lot and quickly put the flames out, but not before 20 cars were burned.

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An arson investigator analyzed evidence at the lot and said the fire was not started intentionally; and believes it may have been sparked by employees cutting metal, or from a cigarette. The exact cause of the fire remains under investigation.

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Damage is estimated to be around $20,000.

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