EL MONTE (CBSLA) — Residents along Strozier Street in El Monte are now finding out why police were at a local warehouse Monday afternoon.

As CBSLA’s Rachel Kim reports, detectives say they busted a huge illegal growhouse. Inside a half-ton of marijuana worth a lot of green: a street value of more than a million dollars.

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“It was hidden really well. I had no idea. I didn’t think anything was going on there at all,” said a neighbor.

A woman who lives nearby didn’t want to be identified but she said she can’t believe what was going on inside the warehouse all this time.

“It’s crazy because I live so close and I have small children,” she said.

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El Monte Police say the solar panel business owner renting the warehouse was actually growing 2,700 marijuana plants. The landlord called police after he wasn’t able to contact the tenant over a building code violation. When they got there, they found the green.

Francisco Ibarra said while he barbecued outside, he had no idea what was cooking next door. He said he smelled the marijuana, but always thought it came from people smoking joints in the area.

Investigators say grow houses usually have their windows covered and air conditioners running around the clock. They say these large recreational cannabis operations aren’t just illegal, they’re dangerous. That’s because grow houses tap into the electrical infrastructure and can cause blackouts, fires and electrocutions.

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“All of a sudden, the lights would go off. All of a sudden, the power would go off,” said a neighbor. “It’s scary not knowing.”