STOCKTON, Calif. (CBS13) — An old, unstable grenade forced a number of businesses to evacuate while explosives experts carefully removed the danger, authorities said.

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The Stockton Police Department said a man drove about 20 miles to turn in a pre-World War II grenade that he found on his property, triggering an alert that led to street closures around Pacific Avenue and evacuations at seven businesses.

Bomb squad members removed the explosive from the man’s pickup truck and transported it to a remote location, where it was safely detonated.

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Discovery Martial Arts instructor David Garmany said the truck was parked near his business while more than 30 kids were in class.

“It was just some person thinking he was going to keep people safe by getting it away from his property, but then he drives it right to my business,” Garmany said. “I was right here in front of my glass windows, and there’s nothing between us and the grenade. That would have been pretty bad.”

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Officers said the man should have left the live explosive where he found it and let authorities investigate it there.