COMANCHE, Texas — A trailer loaded with fireworks exploded Thursday near a Texas high school, killing one person and injuring three other people who were setting up for a Fourth of July show, authorities said.

It's unclear what triggered the explosion, which occurred near a baseball field adjacent to the high school in Comanche, about 100 miles southwest of Fort Worth, fire department spokesman Lt. Marcus Nettleton said. The trailer was hooked to a pickup truck.

Members of the Kiwanis Club were setting up the fireworks for a Friday celebration. Nettleton said one club member died at the scene, and three others were hospitalized with serious injuries. Their names haven't been released.

The club has organized the fireworks show for the past 24 years. Nettleton said there had never been a mishap during the previous events.

Christine Perkins, executive director of the Comanche Chamber of Commerce, said Friday's Fourth of July events have been canceled. She said the fireworks show has been one of the largest in the region, drawing 15,000 people, many from metro areas such as Dallas, Fort Worth and Austin.

“We're still in shock,” she said. “And definitely in a community our size, there will be some kind of ceremony” to recognize the victims," she said.

The agency has a permit on file that authorized Friday's pyrotechnics, said Rachel Moreno, spokeswoman for the fire marshal's office. She declined to release any additional information, citing the ongoing investigation into the explosion.

The Texas fire marshal's office and U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives are investigating, Nettleton said.

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