(Combined Sources) The Greenfield Police Department and the Northwestern District Attorney’s office continues to investigate a residence on Bernardston Road. A marijuana grow operation was discovered after the Greenfield Fire Department responded to a basement fire at the house on Monday afternoon. Massachusetts law allows residents to grow up to six plants. Greenfield Police Chief Robert Haigh has indicated that some of the materials found at the residence suggest that a larger growing operation was in place at the Bernardston Road home.