Police say the incident happened Monday when 19-year-old Sean Michael Ogden was trying to break down fireworks he had purchased so he could turn them into larger fireworks. The blast shook the house of a fire inspector who lives about a quarter-mile away.

Fire marshal Tom Kaufman told The Durango Herald that the friction from the electric grinder could have ignited the mixture.

He said the teen had read online about how larger fireworks could be made from smaller ones.

Odgen is in fair condition at a Denver hospital.