SUN VALLEY (CBS)  — Officials say that a Sun Valley warehouse that caught fire early Sunday was home to a marijuana growing operation that “went up in smoke.”

The fire on Clybourn Ave. was reported just before midnight and soon burned through the roof. Los Angeles firefighters declared the fire out about 12:15 a.m.

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Marijuana Grow Operation Discovered In Warehouse Fire: KNX 1070’s Ed Mertz reports.

Los Angeles police Sgt. Jim Reid said firefighters found several rooms in the 200-by-200-foot warehouse filled with pot plants in various stages of growth, most of which were destroyed.

Police were still able to seize about 140 pounds of plants as evidence, he said.

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Arson investigators determined one of the high-wattage lights used to grow the pot malfunctioned and started the fire, Reid said. It was unclear if anyone was in the building when the fire started.

Reid said the building bore a city permit for pharmaceutical marijuana,but detectives told him there was no such thing, and state law did not permit such a large volume to be grown under any circumstances.

Detectives are expected to try to find out who was behind the growing operation, but Reid said he was “99 percent sure we will be unable to prove who it belonged to.”

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