COMANCHE — In a tragedy that marred the start of the holiday weekend, a trailer loaded with fireworks exploded Thursday near a Texas high school, killing one person and injuring three others who were setting up for a July Fourth show, authorities said.It’s unclear what triggered the explosion, which occurred near a baseball field next to the high school in Comanche, a town of 4,300 about 100 miles southwest of Fort Worth, said Lt. Marcus Nettleton, a Fire Department spokesman. The trailer was hooked to a pickup. He said the explosion occurred around 9 a.m. Members of the Kiwanis Club were setting up the fireworks for a celebration today. Nettleton said one club member died at the scene and three others were hospitalized with serious injuries. Their names haven’t been released. Friends confirmed to WFAA/Channel 8 that the man killed was Russell Reynolds, Comanche’s only chiropractor and licensed pyrotechnician. A black wreath was hung outside his office Thursday afternoon.“He loved this community,” said Leslie Johnson, who worked for Reynolds. “He was instrumental in starting lights down on the square for the people of the town. He was always thinking about other people and not himself.”Reynolds started the fireworks show 24 years ago and was a former president of the Comanche Kiwanis Club, which puts on the show, as well as a church deacon. He was once named the town’s Man of the Year.The club has had no other accidents in the past 24 years, Nettleton said.Christine Perkins, executive director of the Comanche Chamber of Commerce, said today’s July Fourth events have been canceled. She said the fireworks show is one of the largest in the region, drawing 15,000 people, many from metropolitan 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. Rachel Moreno, a spokeswoman for the Texas fire marshal’s office, said the agency has a permit on file that authorized the pyrotechnics. She declined to release further information, citing the investigation into the explosion. The fire marshal’s office and the U.S. Bureau of Alcohol, Tobacco, Firearms and Explosives are investigating, Nettleton said. This report includes material from WFAA/Channel 8.