Nearly 800 marijuana plants found in grow operation next to day care (VIDEO, PHOTOS)

PIERCE COUNTY, Wash. -- Deputies said they discovered a marijuana grow operation with 798 plants Tuesday while assisting Peninsula Light employees shut off power at a Gig Harbor home.

The power company had requested Pierce County sheriff's deputies help while disconnecting power at the home in the 5100 block of Wollochet Drive NW in Gig Harbor. When deputies knocked on the door, they smelled "a strong odor of fresh marijuana."

Pierce County prosecutors said deputies asked the resident, Gian Minh Ly, about the smell. They said Ly claimed he was growing marijuana for medicinal purposes and had 45 or fewer plants.

Ly consented to letting the deputies inside, officials said. They checked the garage and saw where the power had been diverted in the cement floor.

After obtaining a search warrant, deputies returned and discovered an "elaborate three-stage marijuana growing operation powered by an electrical diversion, which was stealing power from the Peninsula Light Company."

Prosecutors said the entire home was "devoted to the cultivation of marijuana" except for the living room, kitchen and an upstairs bathroom.

"The entire basement had been converted into several rooms all used to grow marijuana. An upstairs room contained fans to ventilate the grow operation."

Ly pleaded not guilty to unlawful manufacturing of a controlled substance and third-degree defrauding a public utility.