Two Enka-Candler firefighters suffered burns after a small explosion along Biltmore Lake.
The firefighters were trying to put out a fire in a crevice of the shoreline Tuesday night when they came upon a small, smoldering hole.
As they went to move what appeared to be a fire-starter log, the acid lodged in the crevice of the lake exploded.
The Asheville hazmat team says it was phosphoric acid burrowed in the lake bed. Fire officials believe that when a canister on top of the hole was moved, the acid reacted with air.
Fire officials have advised everyone stay away from the shoreline as an investigation continues.