ASHEVILLE - In six years of volunteering on French Broad River cleanups, Charlie Chang has found plenty of trash, needles and other unpleasant detritus.

But none of it ever blew up on him — until Saturday, that is.

"It was pretty much just like a normal cleanup, to be honest," said Chang, 25. "I didn't find anything big, and then when we were on the last stretch of the river where all the tubers usually are, I found this camping gear-type backpack. I picked it up — nothing unusual about it."

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Chang did not bother to look inside the black knapsack, as he thought it was probably just full of water, rocks or something else mundane. A minute later, mayhem ensued.

"The next thing is, it just exploded," Chang said. "It was just crazy. My feet were touching the backpack."

Luckily, the backpack exploded to the side and forward, so Chang was uninjured. But it was incredibly disorienting — and loud.

"I thought a car had hit the water, to be honest," Chang said. "All I saw was smoke. I ducked and covered. There was fire coming out of the backpack and smoke was everywhere. A lot of people around me thought it was a gunshot."

It was, Chang said, like a scene out of "Breaking Bad," the television series about a high school chemistry teacher whose life spirals downward into a sordid, dangerous world of methamphetamine production and sales.

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Rich Patino was paddling about 25 feet away from Chang when the backpack blew.

"I didn’t see, but I definitely heard it — it was like a boom, like an explosion," Patino said, adding that a white cloud emerged immediately from the bag. "I would definitely compare it to a gunshot."

Despite the tremendous noise, Patino said Chang kept his cool.

"He had a stunned look on his face, but he remained pretty calm, all things being equal," Patino said. "We didn't know what it was. He immediately turned his kayak around, so the powder was going downwind from him. It put out a cloud of white powder for quite some time."

After the explosion, Chang sneaked a peek inside the backpack and saw it was stuffed with plastic soda bottles, mostly Mountain Dew bottles. But several had tubes in them and some had a material that looked like pink sand.

Apparently, Chang had stumbled across a "shake and bake" methamphetamine lab, a portable method of making the highly addictive, illegal stimulant.

Asheville Police Department responded to the incident, which occurred on the section of the river between Jean Webb Park and the new boat dock on Craven Street, in the River Arts District. The APD's Hazardous Devices Team, or bomb squad, responded to the river at Craven Street and Riverside Drive, department spokeswoman Christina Hallingse said.

"The technician that responded located the bag in question and removed it from the river," Hallingse said. "The technician then located several plastic bottles that appeared to have been waste from the manufacture of methamphetamine, so-called 'one pot cooks.'"

Specially trained members of the North Carolina State Bureau of Investigation also responded and disposed of the materials without incident. The APD continues to investigate.

Kelley Klope, spokeswoman for the Asheville Fire Department, said firefighters also responded to the scene.

"Approximately 26 Mountain Dew (20-ounce plastic bottles) were still in the bag and off gassing," Klope said. "The backpack appeared to contain a mobile meth lab."

The city's Bomb Squad pulled the kayak out of the water "to eliminate further exposure to the water," Klope said.

These highly portable meth labs can cause serious health issues.

"The toxic chemicals created in meth labs can cause respiratory problems, burns, eye irritation, and skin irritation to anyone exposed, and if a meth lab catches fire the smoke can carry the chemicals through the air endangering civilians nearby," Klope said.

Chang said the explosion in his kayak occurred about a minute after he picked up the backpack, sometime around 3:15 p.m.

"He was a real trooper," said Eric Bradford, director of operations at Asheville GreenWorks, the nonprofit organization coordinating the river cleanup.

Bradford said GreenWorks employees and volunteers find all sorts of materials in the river, and they have a protocol for dealing with potentially dangerous items such as needles.

"What it does for us is tell us we need to evolve our practices," Bradford said, referring to safety practices. "We're going to be be working with an agent from the SBI on how to spot these hazards, so we can train our volunteers on what to look for."

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GreenWorks has been conducting cleanups for 45 years, and it won't stop doing it because of this incident, he said.

For his part, Chang said he'll keep doing the cleanups "forever." But he will warily regard backpacks in the future, especially any with what appear to be bottles or pink sand in them.

He knows he dodged a potentially very dangerous situation.

"I had a guardian angel, man."