The company that employed five men killed in a fireworks bunker explosion in April could face a $415,200 fine for allowing almost a dozen unsafe working conditions and work practices that may have caused the blast, the state Department of Labor and Industrial Relations said today.

Donaldson Enterprises, Inc. will have an opportunity to contest the charges. The April 8 explosion happened as the employees were taking apart commercial grade cake-style fireworks within a bunker at the Waikele Self Storage.

"We have concluded that there were so many unsafe working conditions and work practices that could have caused the explosion," said Hawaii Occupational Safety and Health Division Administrator Jennifer Shishido. "To continue efforts to find a single cause would neither be productive nor serve our mission of assuring safe and healthful working conditions for every working person in the state."

"At the end of our investigation, we identified 11 potential causes for the explosion, each of which carries a penalty for violating health and safety laws," she said.

The alleged violations include failure to use anti-static materials, provide ample exits, and keep employee cars, which can produce sparks, beyond 50 feet of the bunker entrance.

While the state investigation is complete, federal agencies are still awaiting lab tests on the composition of the fireworks and metallurgical testing of the tools used.