PITTSBURG, Kan. -

Authorities in southeast Kansas say two employees of a fireworks manufacturer were severely burned in an explosion outside the company's former headquarters in Pittsburg Tuesday.

Kenny Clark, 28, has died from his injuries according to the Crawford County Sheriff's office.  They say Howard Harper, 42, remains in critical condition.

Crawford County Undersheriff Steve Geier says the blast occurred at 2:35 p.m. while the employees of Jake's Fireworks were moving materials from a shipping container. The materials were to be transported to the company's new headquarters in a Pittsburg industrial park.

Both victims were transported by helicopter to hospitals for treatment.

Crews extinguished a fire caused by the explosion but planned to remain at the scene overnight. The blast remains under investigation. No other employees were injured during the incident.