POMONA (CBS/AP) — Pomona police say officers responding to a medical emergency call at a commercial building in Pomona found a man dead and more than 2,000 marijuana plants.

Officials say a man called 911 Monday night and told a dispatcher that he was having trouble breathing but did not know his address. After the man’s condition worsened and he could no longer communicate, officers tracked down his location through cell phone towers and GPS coordinates.

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When officers arrived they found the 54-year-old man dead.

Officers found a handgun near the body and noticed an overwhelming smell of marijuana. After obtaining a warrant, officers searched the building and found an elaborate marijuana grow operation with hundreds of plants, including wooden structures to support the cultivation, gallons of fertilizer grow mix, CO2 tanks, special lighting and irrigation in five rooms of the building.

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The investigation is ongoing.

The man’s name was withheld pending family notification.

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