WASHINGTON -- Unused fireworks ignited after the Wednesday evening fireworks display in Washington, injuring three employees.

The U.S. Park Police said one of the workers was flown by helicopter to a nearby hospital with serious burns, CNN reported. A second employee with minor burns was transported by ambulance, while the third employee was treated for minor injuries at the scene.

The accident occurred at what police called a "fire pit" used for the fireworks show, police said.

Copyright © 2007, by United Press International. All Rights Reserved.