An explosion at a dollar store in northwest Mexico on Nov. 1 killed 23 people, including children, and injured a dozen more during the country's vibrant Día de los Muertos festivities, officials and authorities said.

The explosion-turned-fire erupted in downtown Hermosillo, the capital of Sonora state near the western coast of the country, Sonora Gov. Alfonso Durazo said in a video on social media.

The cause of the fire and explosion was not immediately clear. Officials said the fire broke out at a Waldo’s store, a popular discount chain in Mexico. Durazo said in a social media post that he ordered a "thorough and transparent investigation" into the blast.

"This is a sad day for Sonora, especially for the families who lost a loved one at the Waldo’s store in Hermosillo," Durazo said in a post. "I join with respect in the expressions of solidarity with them and with the entire community."

Sonora Attorney General Gustavo Salas said evidence from forensic teams showed the deaths appeared to be a result of inhalation of toxic gases. No evidence, he said, suggested the fire resulted from an attack.

"The working hypothesis is that the event was accidental, and the line of investigation concerns a transformer that was located inside the commercial establishment," his office said in a statement.

Mexican President Claudia Sheinbaum Prado sent her condolences to the families of victims and said she instructed her administration to provide support to the area in a post on X.

Sonora's Red Cross said its 40 staff and 10 ambulances joined in the effort, making six trips to the hospital.

The fire came amid Mexico’s celebrations of Día de los Muertos, or Day of the Dead, a holiday honoring deceased loved ones.

Contributing: Reuters

This article originally appeared on USA TODAY: 23 dead, including children, after dollar store blaze in northwest Mexico

Reporting by Karissa Waddick, USA TODAY / USA TODAY

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