Steve Watters of Brigham City died in the Monday fire, company spokeswoman Melodie DeGuilbert said.
``At about 10:45 p.m., there was an explosion in the research lab where they were working,'' DeGuilbert said, adding that the cause of the blaze and explosion are under investigation.
She declined to reveal the name of the female employee injured in the accident. The woman, who was rescued by Thiokol's on-site emergency response team, is hospitalized with burn injuries at the University of Utah Hospital in Salt Lake City.
The two lab technicians were the only employees present in the research facility at the time of the fire, DeGuilbert said.
Grief counselors were brought in Tuesday.
The damages from the fire will not impact the company's jet propulsion programs, DeGuilbert said. ATK Thiokol Propulsion is supplier of rocket motors for space launch vehicles and strategic missiles.
Watters was the company's first on-the-job fatality since 1987.