ORANGE (CBSLA.com) — An early morning fire burned a research laboratory in the city of Orange Sunday.

Firefighters rushed to the building on N. Batavia Street and W. Barkley Avenue just after 1 a.m.

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When they arrive, flames were about 20 feet above the roof. The fire was so intense that firefighters had to be pulled from the building and battled the blaze with long hoses.

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It took 60 firefighters from more than four agencies more than two hours to douse the flames. The roof was destroyed and windows were blown up by the fire.

Hazmat also responded to the scene as the lab tests oil and water.

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The cause of the fire was not known.