A volunteer helping with cleanup on a river in North Carolina was unhurt after a backpack he retrieved exploded, revealing what police described as a portable methamphetamine lab.

The Asheville Citizen-Times reports Charlie Chang said his feet were on the backpack he plucked out of the French Broad River and placed in his kayak Saturday.

He said he thought it was full of water, rocks or something else. Then, the backpack exploded.

Asheville police say Chang actually had retrieved a “shake and bake” portable methamphetamine lab.

Chang said the backpack was stuffed with plastic soda bottles, several of which had tubes in them and some with a material that looked like pink sand.

Specially trained members of the North Carolina State Bureau of Investigation disposed of the materials without incident.

