OCEANSIDE -- A home fire in northeast Oceanside early today led to the discovery of a garage greenhouse filled with several hundred marijuana plants, authorities said.

A middle-aged man living at the single-story home on Avenida Descanso was taken to an area hospital for treatment of smoke inhalation, according to fire Battalion Chief Pete Lawrence.

He said the man had met firefighters, telling them the blaze reported by neighbors at 12:54 a.m. was out.

However, the first fire crew saw heavy smoke pouring from the roof of the residence.

Lawrence said it took firefighters 15 minutes to knock down the flames, and another hour and 15 minutes to put out the fire. It had gotten into the attic over the well-insulated greenhouse, the battalion chief said.

An arson investigator determined the blaze started in a wall where San Diego Gas & Electric Co. power lines had been illegally tapped for electricity, authorities said.

Damage from the blaze was estimated at $45,000.

Lawrence said none of the marijuana plants burned.

Oceanside police are investigating.