Figuring out the exact nature of a sudden, violent event in February that injured five people at a security products plant in Jamestown, Pennsylvania, is part of an investigation launched by the Occupational Safety and Health Administration, a newspaper in nearby Sharon reports.

OSHA is required to complete an investigation within six months following an accident of this kind that occurred at Combined Systems, Brendan Clayburgh, area director for OSHA, told The Herald.

“It’s still too early to say whether there was an explosion or if it was more of something being over-pressured that may have caused a flash fire,” Clayburgh said. “There’s a little difference associated between those two things and that’s what our investigation will figure out as time goes on.”

Jamestown Fire Chief David Jones told local media in February that the suspected explosion was not accompanied by fire.

Only one of the five injured was admitted to a hospital for treatment after the Feb. 14 incident.

Combined Systems manufactures products for riot control, police tactical teams, corrections officers, and military units.