An illegal indoor cannabis growing operation occupied an entire city block in Corning. On Monday Tehama County D.A. Investigators were assisted by other county agencies and Corning Police as they served a search warrant at the former home of a furniture manufacturing plant on the 1500 block of East Avenue. Numerous grow rooms were built inside the sprawling complex, as well as living quarters for the growers. Investigators say the property had been purchased for $300,000, with another $200,000 spent to prepare it for marijuana cultivation. Investigators reported finding more than 5,000 plants growing under sophisticated lighting and climate control. Asset forfeiture will be sought for the property. Four people were arrested on site without incident, 3 of them from New York and one from Minnesota.